d) an altered targeting domain that selectively binds to a non-Clostridial toxin receptor present on a Clostridial toxin target cell and executes a cell binding step of a Clostridial toxin intoxication process, wherein the altered targeting domain is a glucagon like hormone peptide that selectively binds to a glucagon like hormone receptor; and

e) a protease cleavage site;

wherein cleavage of the protease cleavage site converts the single-chain form of the modified Clostridial toxin into the di-chain form.

Clostridial toxin therapies are successfully used for many indications. Generally, administration of a Clostridial toxin treatment is well tolerated. However, toxin administration in some applications can be challenging because of the larger doses required to achieve a beneficial effect. First, larger doses can increase the likelihood that the toxin may move through the interstitial fluids and the circulatory systems, such as, e.g., the cardiovascular system and the lymphatic system, of the body, resulting in the undesirable dispersal of the toxin to areas not targeted for toxin treatment. Such dispersal can lead to undesirable side effects, such as, e.g., inhibition of neurotransmitter release in neurons not targeted for treatment or paralysis of a muscle not targeted for treatment. For example, a patient administered a therapeutically effective amount of a BoNT/A treatment into the neck muscles for torticollis may develop dysphagia because of dispersal of the toxin into the oropharynx. Thus, there remains a need for improved Clostridial toxins that are effective at the site of treatment, but have negligible to minimal effects in areas not targeted for a toxin treatment.

Second, larger doses of a Clostridial toxin treatment may elicit an antibody response against the toxin. While a potent and effective treatment, the inhibition of neurotransmitter release and the resulting neuromuscular paralysis elicited by Clostridial toxin therapies is not permanent. The reversible nature of these paralytic effects requires periodic treatments in order to maintain the therapeutic benefits from this toxin. As a consequence of this repeated exposure, an immune response against a Clostridial toxin can occur in some patients which reduce or completely prevent the individual's responsiveness to further treatments, see, e.g., Joseph Jankovic, Botulinum toxin: Clinical Implications of Antigenicity and Immunoresistance, (SCIENTIFIC AND THERAPEUTIC ASPECTS OF BOTULINUM TOXIN, 409-415, Mitchell F. Brin et al., eds., Lippincott Williams & Wilkins, 2002); Dirk Dressler, Clinical Presentation and Management of Antibody-induced Failure of Botulinum Toxin Therapy, 19(Suppl. 8) MOV. DISORD. S92-S100 (2004); M. Zouhair Atassi, Basic Immunological Aspects of Botulinum Toxin Therapy, 19(Suppl. 8) MOV. DISORD. S68-S84, (2004). Thus, there remains a need for improved Clostridial toxins that maintain effective therapeutic benefits, but have reduced ability to evoke an immunogenic response against itself.

The growing clinical, therapeutic and cosmetic use of Clostridial toxins in therapies requiring larger doses necessitates the pharmaceutical industry to develop modified Clostridial toxins that are effective at the target site of the application, but reduce or prevent the undesirable side-effects associated with the dispersal of the toxins to an unwanted location or locations. One approach involves modifying a Clostridial toxin so that the modified toxin has an altered cell binding capability for a Clostridial toxin target cell. This altered capability is achieved by replacing the endogenous targeting domain of a naturally-occurring Clostridial toxin with a targeting domain of another molecule that selectively binds to a different receptor present on the surface of a naturally occurring Clostridial toxin target cell. Such a modification to a targeting domain results in a modified toxin that is able to selectively bind to a non-Clostridial toxin receptor (target receptor) present on a Clostridial toxin target cell. An added advantage is achieved when the altered targeting domain is derived from a human targeting domain polypeptide as these polypeptides as less likely to elicit an immunogenic response in a patient. A modified Clostridial toxin with an altered cell binding capability for a Clostridial toxin target cell can bind to a target receptor, translocate into the cytoplasm, and exert its proteolytic effect on the SNARE complex of the Clostridial toxin target cell.

Non-limiting examples of modified Clostridial toxins with an altered cell binding capability for a Clostridial toxin target cell are described in, e.g., Lance E. Steward et al., Modified Clostridial Toxins with Altered Targeting Capabilities For Clostridial Toxin Target Cells, International Patent Application No. 2006/009831 (Mar. 14, 2005); and Lance E. Steward et al., Multivalent Clostridial Toxin Derivatives and Methods of Their Use, U.S. patent application Ser. No. 11/376,696 (Mar. 15, 2006). This altered binding capability for a naturally occurring Clostridial toxin target cell allows for lower effective doses of a modified Clostridial toxin to be administered to an individual because more toxins will be delivered to the target cell. Thus, modified Clostridial toxins with altered cell binding capability for a Clostridial toxin target cell will reduce the undesirable dispersal of the toxin to areas not targeted for treatment, thereby reducing or preventing the undesirable side-effects associated with diffusion of a Clostridial toxin to an unwanted location.

The present invention provides novel Clostridial toxins that reduce or prevent unwanted side-effects associated with toxin dispersal into non-targeted areas. These modified Clostridial toxins comprise, in part, a translocation facilitator domain that enhances the process by which a light chain from a modified toxin translocates into the cytoplasm of a target cell and enzymatically modify its target SNARE substrate. Thus modified Clostridial toxins with an altered cell binding capability for a Clostridial toxin target cell, such as those disclosed in Steward, supra, (Mar. 14, 2006) and Steward, supra, (Mar. 15, 2006), comprising a translocation facilitator domain disclosed in the present specification, exhibit increased potency at the Clostridial toxin target cell and a concomitant reduction of unwanted side-effects associated with toxin dispersal into non-targeted areas. These and related advantages are useful for various clinical, therapeutic and cosmetic applications, such as, e.g., the treatment of neuromuscular disorders, neuropathic disorders, eye disorders, pain, muscle injuries, headache, cardiovascular diseases, neuropsychiatric disorders, endocrine disorders, cancers, otic disorders and hyperkinetic facial lines, as well as, other disorders where administration of a modified Clostridial toxin with an altered cell binding capability for a Clostridial toxin target cell to an individual can produce a beneficial effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic of the current paradigm of neurotransmitter release and Clostridial toxin intoxication in a central and peripheral neuron. FIG. 1A shows a schematic for the neurotransmitter release mechanism of a central and peripheral neuron. The release process can be described as comprising two steps: 1) vesicle docking, where the vesicle-bound SNARE protein of a vesicle containing neurotransmitter molecules associates with the membrane-bound SNARE proteins located at the plasma membrane; and 2) neurotransmitter release, where the vesicle fuses with the plasma membrane and the neurotransmitter molecules are exocytosed. FIG. 1B shows a schematic of the intoxication mechanism for tetanus and botulinum toxin activity in a central and peripheral neuron. This intoxication process can be described as comprising four steps: 1) receptor binding, where a Clostridial toxin binds to a Clostridial receptor and initiates the intoxication process; 2) complex internalization, where after toxin binding, a vesicle containing the toxin/receptor complex is endocytosed into the cell; 3) light chain translocation, where multiple events result in the release of the active light chain into the cytoplasm; and 4) enzymatic target modification, where the active light chain of Clostridial toxin proteolytically cleaves its target SNARE substrate, such as, e.g., SNAP-25, VAMP or Syntaxin, thereby preventing vesicle docking and neurotransmitter release.

FIG. 2 shows the domain organization of naturally-occurring Clostridial toxins. The single chain form depicts the amino to carboxyl linear organization comprising an enzymatic domain, a translocation domain, a HCN translocation facilitating domain and a HCC targeting domain. The di-chain loop region located between the translocation and enzymatic domains is depicted by the double SS bracket. This region comprises an endogenous di-chain loop protease cleavage site that upon proteolytic cleavage with a naturally-occurring protease, such as, e.g., an endogenous Clostridial toxin protease or a naturally-occurring protease produced in the environment, converts the single chain form of the toxin into the di-chain form. As depicted above the single-chain form, the HCC targeting domain comprises the β-trefoil domain which comprises in an amino to carboxyl linear organization of an α-fold, a β4/β5 hairpin turn, a β-fold, a β8/β9 hairpin turn and a γ-fold.

FIG. 4 shows modified Clostridial toxins with an enhanced translocation capability and an altered targeting activity located at the amino terminus of the modified toxin. FIG. 4A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an altered targeting domain, a translocation domain, a translocation facilitating domain and an enzymatic domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the translocation facilitating and enzymatic domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the targeting and translocation domains, the translocation and translocation facilitating domains, translocation facilitating and enzymatic domains or any combination thereof. FIG. 4B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an altered targeting domain, an enzymatic domain, a translocation domain and a translocation facilitating domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the enzymatic and translocation domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the targeting and enzymatic domains, the enzymatic and translocation domains, translocation and translocation facilitating domains or any combination thereof.

FIG. 5 shows modified Clostridial toxins with an enhanced translocation capability and an altered targeting activity located between two other domains. FIG. 5A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an enzymatic domain, an altered targeting domain, a translocation domain and a translocation facilitating domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the enzymatic and targeting domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the enzymatic and targeting domains, the targeting and translocation domains, the translocation and translocation facilitating domains or any combination thereof. FIG. 5B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a translocation domain, a translocation facilitating domain, an altered targeting domain and an enzymatic domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the translocation facilitating and targeting domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the translocation and translocation facilitating domains, the translocation facilitating and targeting domains, the targeting and enzymatic domains or any combination thereof.

FIG. 6 shows modified Clostridial toxins with an enhanced translocation capability and an altered targeting activity located at the carboxyl terminus of the modified toxin. FIG. 6A depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising an enzymatic domain, a translocation domain, a translocation facilitating domain and an altered targeting domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the enzymatic and translocation domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the enzymatic and translocation domains, the translocation and translocation facilitating domains, the translocation facilitating and targeting domains or any combination thereof. FIG. 6B depicts the single polypeptide form of a modified Clostridial toxin with an amino to carboxyl linear organization comprising a translocation domain, a translocation facilitating domain, an enzymatic domain and an altered targeting domain, with the di-chain loop region depicted by the double SS bracket. A proteolytic cleavage site (P) within a di-chain loop region is located between the translocation facilitating and enzymatic domains. Upon proteolytic cleavage with a P protease, the single chain form of the toxin is converted to the di-chain form. The P protease site can be a Clostridial toxin endogenous protease cleavage site or a non-Clostridial toxin exogenous protease cleavage site. Spacers can be placed between the translocation and translocation facilitating domains, the translocation facilitating and enzymatic domains, the enzymatic and targeting domains or any combination thereof.

Clostridia toxins produced by Clostridium botulinum, Clostridium tetani, Clostridium baratii and Clostridium butyricum are the most widely used in therapeutic and cosmetic treatments of humans and other mammals. Strains of C. botulinum produce seven antigenically-distinct types of Botulinum toxins (BoNTs), which have been identified by investigating botulism outbreaks in man (BoNT/A, /B, /E and /F), animals (BoNT/C1 and /D), or isolated from soil (BoNT/G). While all seven botulinum toxins (BoNT) serotypes have similar structure and pharmacological properties, each also displays heterogeneous bacteriological characteristics. In contrast, tetanus toxin (TeNT) is produced by a uniform group of C. tetani. Two other species of Clostridia, C. baratii and C. butyricum, also produce toxins similar to BoNT/F and BoNT/E, respectively.

TABLE 1

Clostridial Toxin Reference Sequences and Regions

SEQ

ID

HC

Toxin

NO:

LC

HN

HCN

HCC

BoNT/

1

M1-K448

A449-I873

I874-P1110

Y1111-L1296

A

BoNT/

2

M1-K441

A442-I860

L861-E1097

Y1098-E1291

B

BoNT/

3

M1-K449

T450-I868

N869-E1111

Y1112-E1291

C1

BoNT/

4

M1-R445

D446-I864

N865-E1098

Y1099-E1276

D

BoNT/E

5

M1-R422

K423-I847

K848-E1085

Y1086-K1252

BoNT/F

6

M1-K439

A440-I866

K867-K1105

Y1106-E1274

BoNT/

7

M1-K446

S447-I865

S866-Q1105

Y1106-E1297

G

TeNT

8

M1-A457

S458-L881

K882-E1127

Y1128-D1315

Clostridia toxins possess approximately 35% amino acid identity with each other and share the same functional domain organization and overall structural architecture. Clostridial toxins are each translated as a single chain polypeptide of approximately 150 kDa that is subsequently cleaved by proteolytic scission within a disulfide loop by a naturally-occurring protease, such as, e.g., an endogenous Clostridial toxin protease or a naturally-occurring protease produced in the environment (see FIG. 2). This posttranslational processing yields a di-chain molecule comprising an approximately 50 kDa light chain (LC) and an approximately 100 kDa heavy chain (HC) held together by a single disulfide bond and noncovalent interactions. It is widely held that the mature di-chain molecule comprises three functionally distinct domains: 1) an enzymatic domain located in the LC that includes a metalloprotease region containing a zinc-dependent endopeptidase activity which specifically targets core components of the neurotransmitter release apparatus (Table 1); 2) a translocation domain contained within the amino-terminal half of the heavy chain (HN domain) that facilitates release of the LC from intracellular vesicles into the cytoplasm of the target cell (Table 1); and 3) a binding domain found within the carboxyl-terminal half of the heavy chain (HC domain) that determines the binding activity and binding specificity of the toxin to the receptor complex located at the surface of the target cell (Table 1), see, e.g., Kathryn Turton et al., Botulinum and Tetanus Neurotoxins: Structure, Function and Therapeutic Utility, 27(11) Trends Biochem. Sci. 552-558. (2002); John A. Chaddock and P. M. H. Marks, Clostridial Neurotoxins: Structure-Function Led Design of New Therapeutics, 63(5) Cell. Mol. Life. Sci. 540-551 (2006); and Keith Foster et al., Re-engineering the Target Specificity of Clostridial Neurotoxins—A Route To Novel Therapeutics, 9(2-3) Neurotox Res. 101-107 (2006).

The binding, translocation and enzymatic activities of a Clostridial toxin are all necessary to execute the overall cellular intoxication mechanism whereby Clostridial toxins enter a neuron and inhibit neurotransmitter release is similar, regardless of serotype or subtype. The current paradigm describes the intoxication mechanism as comprising at least four steps: 1) receptor binding, 2) complex internalization, 3) light chain translocation, and 4) enzymatic target modification (see FIG. 1). The process is initiated when the HC domain of a Clostridial toxin binds to a toxin-specific receptor located on the plasma membrane surface of a target cell. The binding specificity of a receptor complex is thought to be achieved, in part, by specific combinations of gangliosides and protein receptors that appear to distinctly comprise each Clostridial toxin receptor complex. Once bound, the toxin/receptor complexes are internalized by endocytosis and the internalized vesicles are sorted to specific intracellular routes. The translocation step, now thought to be mediated by the HN domain and further facilitated by the HCN domain, appears to be triggered by the acidification of the vesicle compartment. This process seems to initiate two important pH-dependent structural rearrangements that increase hydrophobicity and promote separation of the light chain from the heavy chain of the toxin. Once activated, light chain endopeptidase of the toxin is released from the intracellular vesicle into the cytosol where it appears to specifically target one of three known core components of the neurotransmitter release apparatus. These core proteins, vesicle-associated membrane protein (VAMP)/synaptobrevin, synaptosomal-associated protein of 25 kDa (SNAP-25) and Syntaxin, are necessary for synaptic vesicle docking and fusion at the nerve terminal and constitute members of the soluble N-ethylmaleimide-sensitive factor-attachment protein-receptor (SNARE) family. BoNT/A and BoNT/E cleave SNAP-25 in the carboxyl-terminal region, releasing a nine or twenty-six amino acid segment, respectively, and BoNT/C1 also cleaves SNAP-25 near the carboxyl-terminus. The botulinum serotypes BoNT/B, BoNT/D, BoNT/F and BoNT/G, and tetanus toxin, act on the conserved central portion of VAMP, and release the amino-terminal portion of VAMP into the cytosol. BoNT/C1 cleaves syntaxin at a single site near the cytosolic membrane surface. The selective proteolysis of synaptic SNAREs accounts for the block of neurotransmitter release caused by Clostridial toxins in vivo. The SNARE protein targets of Clostridial toxins are common to exocytosis in a variety of non-neuronal types; in these cells, as in neurons, light chain peptidase activity inhibits exocytosis, see, e.g., Yann Humeau et al., How Botulinum and Tetanus Neurotoxins Block Neurotransmitter Release, 82(5) Biochimie. 427-446 (2000); and Giovanna Lalli et al., The Journey of Tetanus and Botulinum Neurotoxins in Neurons, 11(9) Trends Microbiol. 431-437, (2003).

The three-dimensional crystal structures of BoNT/A, BoNT/B and the HC domain of TeNT indicate that the three functional domains of Clostridial neurotoxins are structurally distinct. The HEXXH consensus motif of the light chain forms the tetrahedral zinc binding pocket of the catalytic site located in a deep cleft on the protein surface that is accessible by a channel. The structure of the HN and HC domains consists primarily of β-sheet topologies that are linked by a single α-helix. The cylindrical-shaped HN domain comprises two long amphipathic α-helices that resemble the coiled-coil motif found in some viral proteins. The HN domain also forms a long unstructured loop called the ‘translocation belt,’ which wraps around a large negatively charged cleft of the light chain that blocks access of the zinc atom to the catalytic-binding pocket of active site. The HC domain comprises two distinct structural features of roughly equal size that indicate function. The first, designated the HCN domain, is located in the amino half of the HC domain. The HCN domain forms a β-barrel, jelly-roll fold. The HCC domain is the second domain that comprises the HC domain. This carboxyl-terminal domain comprises a modified β-trefoil domain which forms three distinct carbohydrate binding regions that resembles the carbohydrate binding moiety found in many sugar-binding proteins, such as, e.g., serum amyloid P, sialidase, cryia, insecticidal ∂-endotoxin and lectins. Biochemical studies indicate that the β-trefoil domain structure of the HCC domain appears to mediate the binding to specific carbohydrate containing components of the Clostridial toxin receptor on the cell surface, see, e.g., Krzysztof Ginalski et al., Structure-based Sequence Alignment for the Beta-Trefoil Subdomain of the Clostridial Neurotoxin Family Provides Residue Level Information About the Putative Ganglioside Binding Site, 482(1-2) FEBS Lett. 119-124 (2000). The HC domain tilts away from the HN domain exposing the surface loops and making them accessible for binding. No contacts occur between the light chain and the HC domain.

We know that only the HCC domain participates in receptor binding because the β-trefoil domains are restricted to this domain. Proteins containing the structural β-trefoil domain represents a diverse group of proteins organized into at least eight superfamilies including the cytokines, MIR domain proteins, Ricin B-like lectins, agglutinins, Soybean trypsin inhibitor like proteins, Actin-crosslinking proteins, LAG-1 proteins and AbfB domain proteins, see, e.g., C. A. Orengo et al., Protein Superfamilies and Domain Superfolds, 372 Nature 631-634 (1994); and Alexey G. Murzin et al., SCOP: A Structural Classification of Proteins Database for the Investigation of Sequences and Structures, 247(4) J. Mol. Biol. 536-540 (1995). While having diverse cellular roles, members of these superfamilies mechanistically function via protein-protein associations through the β-trefoil domain. Of particular interest is the fact that many of these members are specifically involved in receptor interactions, including, e.g., the cytokine superfamily members Fibroblast Growth Factors (FGFs) and the Interleukin-1s (IL-1s); the Ricin B-like lectins; the agglutinins; and STI-like members the Kunitz inhibitors and Clostridium neurotoxins. That only the HCC domain alone mediates the cell binding step of intoxication is further supported by the finding that mutations that disrupt the receptor binding activity of Clostridial toxins have been confined to the HCC domain, see, e.g., Andreas Rummel et al., The HCC-Domain of Botulinum Neurotoxins A and B Exhibits a Singular Ganglioside Binding Site Displaying Serotype Specific Carbohydrate Interaction, 51(3) Mol. Microbiol. 631-643 (2004).

Because the HCC domain appears not only necessary, but sufficient for selective binding of a Clostridial toxin to its receptor, we have deduced that the primary function of the HCN domain of Clostridial toxins is involved in the translocation step of the intoxication process, and not in the cell binding step, because the lack of HCN domain appears to reduce intoxication efficiency. For example, a modified BoNT/A comprising a Substance P targeting domain was inefficient in intoxicating its corresponding target cells. In this modified toxin, the entire BoNT/A HC domain, comprising both the BoNT/A HCC domain and the BoNT/A HCN domain, was replaced by the Substance P targeting domain. Likewise, we have determined that several other modified Clostridial toxins that have replaced the entire BoNT/A HC domain with an exogenous targeting domain have exhibited reduced intoxication capabilities. Thus, the HCN domain possess a translocation facilitating function because 1) HCC domain primarily mediates the receptor binding step of the intoxication process; 2) modified Clostridial toxins lacking the HCN domain exhibit a reduced ability to translocate into the cytoplasm as evident by such modified toxins exhibiting decreased proteolysis of their SNARE substrates; and 3) the LC domain mediates the enzymatic activity of the toxin. While the exact translocation facilitating mechanism of the HCN domain is currently not understood, the HCN domain may 1) participate in the formation of an endosomal pore; 2) mediate the insertion of the pore into a vesicle membrane; 3) assist in the delivery of LC across the endosomal membrane and/or 4) serve as a structural scaffold or spacer that facilitates the appropriate orientation a the targeting domain in relationship to the translocation domain. In this last point, the HCN domain would serve to orient the translocation domain to facilitate the proper presentation of the translocation domain for insertion into the membrane following binding of the ligand by the receptor. This novel role of the HCN domain in the translocation step is contrary to the widely accepted view that the Clostridial toxin HCN domain played an integral role in the cell binding step of the intoxication process.

Thus, the present invention discloses modified Clostridial toxins that exhibit 1) an enhanced translocation capability; and 2) an altered targeting capability for a naturally-occurring Clostridial toxin target cell. The enhanced translocation capability is mediated by a translocation facilitating domain comprising, e.g., a HCN region of Clostridial toxins. The HCN domain enhances the process by which the HN domain mediates the release of the light chain from internalized intracellular vesicles into the cytoplasm of the target cell during the translocation step. Enhanced translocation capability is obtained by including or maintaining a Clostridial toxin HCN domain in a modified Clostridial toxin disclosed in the present specification. The altered targeting capability for a naturally-occurring Clostridial toxin target cell is mediated by an altered targeting domain comprising a modified HCC targeting domain of Clostridial toxins. The HCC domain primarily determines the binding activity and binding specificity of the toxin to the receptor complex located at the surface of the target cell. Altered targeting activity is achieved by replacing a naturally-occurring HCC targeting domain of a Clostridial toxin with a binding domain for a non-Clostridial toxin receptor present on a Clostridial toxin target cell

Both the enhanced translocation and altered targeting activity should allow lower effective doses of a modified Clostridial toxin to be administered to an individual because more toxin will be delivered to a target cell. Thus modified Clostridial toxins with enhanced translocation and binding capabilities will reduce the undesirable dispersal of the toxin to areas not targeted for treatment, thereby reducing or preventing the undesirable side-effects associated with diffusion of a Clostridial toxin to an unwanted location.

Thus, aspects of the present invention provide modified Clostridial toxins comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain, a translocation facilitating domain and an altered targeting domain, wherein the modified Clostridial toxin exhibits a binding activity for a non-Clostridial toxin receptor present on a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin. It is envisioned that any translocation facilitating domain capable of further facilitating the translocation step of the intoxication process where the light chain is released from intracellular vesicles into the cytoplasm of the target cell will be useful to practice aspects of the present invention, including, without limitation, a Clostridial toxin translocation facilitating domain and an enveloped virus fusogenic peptide domain. Likewise, a multitude of altered targeting domains are envisioned, including, without limitation, altered targeting domains that bind a receptor present on a presynaptic membrane, such as, e.g., Glucagon like hormones, neurohormones, neuroregulatory cytokines, neurotrophins, growth factors, axon guidance signaling molecules, sugar binding proteins, ligands that selectively bind neurexins and WNTs; and altered targeting domains that bind a receptor present on a postsynaptic membrane, such as, e.g., Ng-CAM(L1), NCAM, N-cadherin, Agrin-MUSK, basement membrane polypeptides. It is also envisioned that the location of the altered targeting domain in the modified Clostridial toxins of the present specification can be located at the amino terminus of the toxin, between the enzymatic and translocation domains or at the carboxyl terminus of the toxin. Thus, a modified Clostridial toxins disclosed in the present specification can comprise an amino to carboxyl domain arrangement of, e.g., an altered targeting domain, a Clostridial toxin translocation domain, a translocation facilitating domain and a Clostridial toxin enzymatic domain; an altered targeting domain, a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and a translocation facilitating domain; a Clostridial toxin enzymatic domain, an altered targeting domain, a Clostridial toxin translocation domain and a translocation facilitating domain; a Clostridial toxin translocation domain, a translocation facilitating domain, an altered targeting domain and a Clostridial toxin enzymatic domain; a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain, a translocation facilitating domain and an altered targeting domain; and a Clostridial toxin translocation domain, a translocation facilitating domain, a Clostridial toxin enzymatic domain and an altered targeting domain.

Other aspects of the present invention provide polynucleotide molecules encoding modified Clostridial toxins comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain, a translocation facilitating domain and an altered targeting domain, wherein the modified Clostridial toxin exhibits a binding activity for a non-Clostridial toxin receptor present on a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin. It is envisioned that the location of the altered targeting domain of the modified Clostridial toxins encoded by polynucleotide molecules of the present specification can be located at the amino terminus of the toxin, between the enzymatic and translocation domains or at the carboxyl terminus of the toxin.

Other aspects of the present invention provide methods of producing a modified Clostridial toxin disclosed in the present specification, the method comprising the step of expressing in a cell a polynucleotide molecule encoding a modified Clostridial toxin comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain, a translocation facilitating domain and an altered targeting domain, wherein the modified Clostridial toxin exhibits a binding activity for a non-Clostridial toxin receptor present on a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin. Other aspects of the present invention provide methods of producing a modified Clostridial toxin disclosed in the present specification, the method comprising the steps of introducing in a cell an expression construct comprising a polynucleotide molecule encoding a modified Clostridial toxin comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain, a translocation facilitating domain and an altered targeting domain, wherein the modified Clostridial toxin exhibits a binding activity for a non-Clostridial toxin receptor present on a Clostridial toxin target cell relative to a naturally-occurring Clostridial toxin and expressing the expression construct in the cell.

Aspects of the present invention provide, in part, a modified Clostridial toxin. As used herein, the term “modified Clostridial toxin” means any polypeptide that can execute the overall cellular mechanism whereby a Clostridial toxin enters a neuron and inhibits neurotransmitter release and encompasses the binding of a Clostridial toxin to a low or high affinity receptor complex, the internalization of the toxin, the translocation of the Clostridial toxin light chain into the cytoplasm and the enzymatic modification of a Clostridial toxin substrate. A modified Clostridial toxin disclosed in the present specification is distinguished from a naturally-occurring Clostridial toxin by the fact that a modified Clostridial toxin comprises a translocation facilitating domain that enhances the process by which a light chain from a modified toxin translocates into the cytoplasm of a target cell and a modified Clostridial toxin lacks the cell binding activity of a naturally-occurring binding domain found in a Clostridial toxin. Instead, a modified Clostridial toxin disclosed in the present specification comprises an altered targeting domain that determines the binding activity of the modified Clostridial toxin to an endogenous Clostridial toxin receptor located at the surface of the target cell. By definition, a naturally-occurring Clostridial toxin lacks an altered targeting domain. Examples of modified Clostridial toxin are described in, e.g., Lance E. Steward et al., Modified Clostridial Toxins with Altered Targeting Capabilities For Clostridial Toxin Target Cells, International Patent Application No. 2006/009831 (Mar. 14, 2005); and Lance E. Steward et al., Multivalent Clostridial Toxin Derivatives and Methods of Their Use, U.S. patent application Ser. No. 11/376,696 (Mar. 15, 2006). Any of the modified Clostridial toxins described in, e.g., Steward, supra, (Mar. 14, 2006) and Steward, supra, (Mar. 15, 2006), can be further modified to include a translocation facilitating domain as disclosed in the present specification.

As used herein, the term “Clostridial toxin light chain variant,” whether naturally-occurring or non-naturally-occurring, means a Clostridial toxin light chain that has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 1) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial toxin light chain variants disclosed in the present specification are capable of executing the enzymatic target modification step of the intoxication process. As non-limiting examples, a BoNT/A light chain variant comprising amino acids 1-448 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-448 of SEQ ID NO: 1; a BoNT/B light chain variant comprising amino acids 1-441 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-441 of SEQ ID NO: 2; a BoNT/C1 light chain variant comprising amino acids 1-449 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-449 of SEQ ID NO: 3; a BoNT/D light chain variant comprising amino acids 1-445 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-445 of SEQ ID NO: 4; a BoNT/E light chain variant comprising amino acids 1-422 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-422 of SEQ ID NO: 5; a BoNT/F light chain variant comprising amino acids 1-439 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-439 of SEQ ID NO: 6; a BoNT/G light chain variant comprising amino acids 1-446 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-446 of SEQ ID NO: 7; and a TeNT light chain variant comprising amino acids 1-457 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1-457 of SEQ ID NO: 8.

It is recognized by those of skill in the art that within each serotype of Clostridial toxin there can be naturally occurring Clostridial toxin light chain variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific light chain subtypes showing approximately 95% amino acid identity when compared to another BoNT/A light chain subtype. As used herein, the term “naturally occurring Clostridial toxin light chain variant” means any Clostridial toxin light chain produced by a naturally-occurring process, including, without limitation, Clostridial toxin light chain isoforms produced from alternatively-spliced transcripts, Clostridial toxin light chain isoforms produced by spontaneous mutation and Clostridial toxin light chain subtypes. A naturally occurring Clostridial toxin light chain variant can function in substantially the same manner as the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant is based, and can be substituted for the reference Clostridial toxin light chain in any aspect of the present invention. A naturally occurring Clostridial toxin light chain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant is based. A naturally occurring Clostridial toxin light chain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin light chain on which the naturally occurring Clostridial toxin light chain variant is based.

A non-limiting examples of a naturally occurring Clostridial toxin light chain variant is a Clostridial toxin light chain isoform such as, e.g., a BoNT/A light chain isoform, a BoNT/B light chain isoform, a BoNT/C1 light chain isoform, a BoNT/D light chain isoform, a BoNT/E light chain isoform, a BoNT/F light chain isoform, a BoNT/G light chain isoform, and a TeNT light chain isoform. A Clostridial toxin light chain isoform can function in substantially the same manner as the reference Clostridial toxin light chain on which the Clostridial toxin light chain isoform is based, and can be substituted for the reference Clostridial toxin light chain in any aspect of the present invention.

Another non-limiting examples of a naturally occurring Clostridial toxin light chain variant is a Clostridial toxin light chain subtype such as, e.g., a light chain from subtype BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4; a light chain from subtype BoNT/B1, BoNT/B2, BoNT/B bivalent and BoNT/B nonproteolytic; a light chain from subtype BoNT/C1-1 and BoNT/C1-2; a light chain from subtype BoNT/E1, BoNT/E2 and BoNT/E3; and a light chain from subtype BoNT/F1, BoNT/F2, BoNT/F3 and BoNT/F4. A Clostridial toxin light chain subtype can function in substantially the same manner as the reference Clostridial toxin light chain on which the Clostridial toxin light chain subtype is based, and can be substituted for the reference Clostridial toxin light chain in any aspect of the present invention.

As used herein, the term “conservative Clostridial toxin light chain variant” means a Clostridial toxin light chain that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial toxin light chain sequence (Table 1). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial toxin light chain variant can function in substantially the same manner as the reference Clostridial toxin light chain on which the conservative Clostridial toxin light chain variant is based, and can be substituted for the reference Clostridial toxin light chain in any aspect of the present invention. A conservative Clostridial toxin light chain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin light chain on which the conservative Clostridial toxin light chain variant is based. A conservative Clostridial toxin light chain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin light chain on which the conservative Clostridial toxin light chain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin light chain on which the conservative Clostridial toxin light chain variant is based. Non-limiting examples of a conservative Clostridial toxin light chain variant include, e.g., conservative BoNT/A light chain variants, conservative BoNT/B light chain variants, conservative BoNT/C1 light chain variants, conservative BoNT/D light chain variants, conservative BoNT/E light chain variants, conservative BoNT/F light chain variants, conservative BoNT/G light chain variants, and conservative TeNT light chain variants.

As used herein, the term “non-conservative Clostridial toxin light chain variant” means a Clostridial toxin light chain in which 1) at least one amino acid is deleted from the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based; 2) at least one amino acid added to the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial toxin light chain sequence (Table 1). A non-conservative Clostridial toxin light chain variant can function in substantially the same manner as the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based, and can be substituted for the reference Clostridial toxin light chain in any aspect of the present invention. A non-conservative Clostridial toxin light chain variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. A non-conservative Clostridial toxin light chain variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. A non-conservative Clostridial toxin light chain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. A non-conservative Clostridial toxin light chain variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin light chain on which the non-conservative Clostridial toxin light chain variant is based. Non-limiting examples of a non-conservative Clostridial toxin light chain variant include, e.g., non-conservative BoNT/A light chain variants, non-conservative BoNT/B light chain variants, non-conservative BoNT/C1 light chain variants, non-conservative BoNT/D light chain variants, non-conservative BoNT/E light chain variants, non-conservative BoNT/F light chain variants, non-conservative BoNT/G light chain variants, and non-conservative TeNT light chain variants.

As used herein, the term “Clostridial toxin light chain chimeric” means a polypeptide comprising at least a portion of a Clostridial toxin light chain and at least a portion of at least one other polypeptide to form a toxin light chain with at least one property different from the reference Clostridial toxin light chains of Table 1, with the proviso that this Clostridial toxin light chain chimeric is still capable of specifically targeting the core components of the neurotransmitter release apparatus and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. Such Clostridial toxin light chain chimerics are described in, e.g., Lance E. Steward et al., Leucine-based Motif and Clostridial Toxins, U.S. Patent Publication 2003/0027752 (Feb. 6, 2003); Lance E. Steward et al., Clostridial Neurotoxin Compositions and Modified Clostridial Neurotoxins, U.S. Patent Publication 2003/0219462 (Nov. 27, 2003); and Lance E. Steward et al., Clostridial Neurotoxin Compositions and Modified Clostridial Neurotoxins, U.S. Patent Publication 2004/0220386 (Nov. 4, 2004).

As used herein, the term “active Clostridial toxin light chain fragment” means any of a variety of Clostridial toxin fragments comprising the light chain can be useful in aspects of the present invention with the proviso that these light chain fragments can specifically target the core components of the neurotransmitter release apparatus and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. The light chains of Clostridial toxins are approximately 420-460 amino acids in length and comprise an enzymatic domain (Table 1). Research has shown that the entire length of a Clostridial toxin light chain is not necessary for the enzymatic activity of the enzymatic domain. As a non-limiting example, the first eight amino acids of the BoNT/A light chain (residues 1-8 of SEQ ID NO: 1) are not required for enzymatic activity. As another non-limiting example, the first eight amino acids of the TeNT light chain (residues 1-8 of SEQ ID NO: 8) are not required for enzymatic activity. Likewise, the carboxyl-terminus of the light chain is not necessary for activity. As a non-limiting example, the last 32 amino acids of the BoNT/A light chain (residues 417-448 of SEQ ID NO: 1) are not required for enzymatic activity. As another non-limiting example, the last 31 amino acids of the TeNT light chain (residues 427-457 of SEQ ID NO: 8) are not required for enzymatic activity. Thus, aspects of this embodiment can include Clostridial toxin light chains comprising an enzymatic domain having a length of, e.g., at least 350 amino acids, at least 375 amino acids, at least 400 amino acids, at least 425 amino acids and at least 450 amino acids. Other aspects of this embodiment can include Clostridial toxin light chains comprising an enzymatic domain having a length of, e.g., at most 350 amino acids, at most 375 amino acids, at most 400 amino acids, at most 425 amino acids and at most 450 amino acids.

Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring Clostridial toxin light chain variants and non-naturally-occurring Clostridial toxin light chain variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein.

Aspects of the present invention provide, in part, a Clostridial toxin translocation domain. As used herein, the term “Clostridial toxin translocation domain” means any Clostridial toxin polypeptide that can execute the translocation step of the intoxication process that mediates Clostridial toxin light chain translocation. Thus, a Clostridial toxin translocation domain facilitates the movement of a Clostridial toxin light chain across a membrane and encompasses the movement of a Clostridial toxin light chain through the membrane an intracellular vesicle into the cytoplasm of a cell. Non-limiting examples of a Clostridial toxin translocation domain include, e.g., a Clostridial toxin HN region such as, e.g., a BoNT/A HN region, a BoNT/B HN region, a BoNT/C1 HN region, a BoNT/D HN region, a BoNT/E HN region, a BoNT/F HN region, a BoNT/G HN region, and a TeNT HN region.

As used herein, the term “Clostridial toxin HN region variant,” whether naturally-occurring or non-naturally-occurring, means a Clostridial toxin HN region that has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 1) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial toxin HN region variants disclosed in the present specification are capable of executing the translocation step of the intoxication process that mediates Clostridial toxin light chain translocation. As non-limiting examples, a BoNT/A HN region variant comprising amino acids 449-873 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 449-873 of SEQ ID NO: 1; a BoNT/B HN region variant comprising amino acids 442-860 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 442-860 of SEQ ID NO: 2; a BoNT/C1 HN region variant comprising amino acids 450-868 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 450-868 of SEQ ID NO: 3; a BoNT/D HN region variant comprising amino acids 446-864 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 446-864 of SEQ ID NO: 4; a BoNT/E HN region variant comprising amino acids 423-847 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 423-847 of SEQ ID NO: 5; a BoNT/F HN region variant comprising amino acids 440-866 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 440-866 of SEQ ID NO: 6; a BoNT/G HN region variant comprising amino acids 447-865 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 447-865 of SEQ ID NO: 7; and a TeNT HN region variant comprising amino acids 458-881 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 458-881 of SEQ ID NO: 8.

It is recognized by those of skill in the art that within each serotype of Clostridial toxin there can be naturally occurring Clostridial toxin HN region variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific HN region subtypes showing approximately 87% amino acid identity when compared to another BoNT/A HN region subtype. As used herein, the term “naturally occurring Clostridial toxin HN region variant” means any Clostridial toxin HN region produced by a naturally-occurring process, including, without limitation, Clostridial toxin HN region isoforms produced from alternatively-spliced transcripts, Clostridial toxin HN region isoforms produced by spontaneous mutation and Clostridial toxin HN region subtypes. A naturally occurring Clostridial toxin HN region variant can function in substantially the same manner as the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention. A naturally occurring Clostridial toxin HN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based. A naturally occurring Clostridial toxin HN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HN region on which the naturally occurring Clostridial toxin HN region variant is based.

A non-limiting examples of a naturally occurring Clostridial toxin HN region variant is a Clostridial toxin HN region isoform such as, e.g., a BoNT/A HN region isoform, a BoNT/B HN region isoform, a BoNT/C1 HN region isoform, a BoNT/D HN region isoform, a BoNT/E HN region isoform, a BoNT/F HN region isoform, a BoNT/G HN region isoform, and a TeNT HN region isoform. A Clostridial toxin HN region isoform can function in substantially the same manner as the reference Clostridial toxin HN region on which the Clostridial toxin HN region isoform is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention.

Another non-limiting examples of a naturally occurring Clostridial toxin HN region variant is a Clostridial toxin HN region subtype such as, e.g., a HN region from subtype BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4; a HN region from subtype BoNT/B1, BoNT/B2, BoNT/B bivalent and BoNT/B nonproteolytic; a HN region from subtype BoNT/C1-1 and BoNT/C1-2; a HN region from subtype BoNT/E1, BoNT/E2 and BoNT/E3; and a HN region from subtype BoNT/F1, BoNT/F2, BoNT/F3 and BoNT/F4. A Clostridial toxin HN region subtype can function in substantially the same manner as the reference Clostridial toxin HN region on which the Clostridial toxin HN region subtype is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention.

As used herein, the term “conservative Clostridial toxin HN region variant” means a Clostridial toxin HN region that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial toxin HN region sequence (Table 1). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial toxin HN region variant can function in substantially the same manner as the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention. A conservative Clostridial toxin HN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant is based. A conservative Clostridial toxin HN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HN region on which the conservative Clostridial toxin HN region variant is based. Non-limiting examples of a conservative Clostridial toxin HN region variant include, e.g., conservative BoNT/A HN region variants, conservative BoNT/B HN region variants, conservative BoNT/C1 HN region variants, conservative BoNT/D HN region variants, conservative BoNT/E HN region variants, conservative BoNT/F HN region variants, conservative BoNT/G HN region variants, and conservative TeNT HN region variants.

As used herein, the term “non-conservative Clostridial toxin HN region variant” means a Clostridial toxin HN region in which 1) at least one amino acid is deleted from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based; 2) at least one amino acid added to the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial toxin HN region sequence (Table 1). A non-conservative Clostridial toxin HN region variant can function in substantially the same manner as the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based, and can be substituted for the reference Clostridial toxin HN region in any aspect of the present invention. A non-conservative Clostridial toxin HN region variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based. A non-conservative Clostridial toxin HN region variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based. A non-conservative Clostridial toxin HN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based. A non-conservative Clostridial toxin HN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HN region on which the non-conservative Clostridial toxin HN region variant is based. Non-limiting examples of a non-conservative Clostridial toxin HN region variant include, e.g., non-conservative BoNT/A HN region variants, non-conservative BoNT/B HN region variants, non-conservative BoNT/C1 HN region variants, non-conservative BoNT/D HN region variants, non-conservative BoNT/E HN region variants, non-conservative BoNT/F HN region variants, non-conservative BoNT/G HN region variants, and non-conservative TeNT HN region variants.

As used herein, the term “Clostridial toxin HN region chimeric” means a polypeptide comprising at least a portion of a Clostridial toxin HN region and at least a portion of at least one other polypeptide to form a toxin HN region with at least one property different from the reference Clostridial toxin HN regions of Table 1, with the proviso that this Clostridial toxin HN region chimeric is still capable of facilitating the release of the LC from intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate.

As used herein, the term “active Clostridial toxin HN region fragment” means any of a variety of Clostridial toxin fragments comprising the HN region can be useful in aspects of the present invention with the proviso that these active fragments can facilitate the release of the LC from intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. The HN regions from the heavy chains of Clostridial toxins are approximately 410-430 amino acids in length and comprise a translocation domain (Table 1). Research has shown that the entire length of a HN region from a Clostridial toxin heavy chain is not necessary for the translocating activity of the translocation domain. Thus, aspects of this embodiment can include Clostridial toxin HN regions comprising a translocation domain having a length of, e.g., at least 350 amino acids, at least 375 amino acids, at least 400 amino acids and at least 425 amino acids. Other aspects of this embodiment can include Clostridial toxin HN regions comprising translocation domain having a length of, e.g., at most 350 amino acids, at most 375 amino acids, at most 400 amino acids and at most 425 amino acids.

Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring Clostridial toxin HN region variants and non-naturally-occurring Clostridial toxin HN region variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein.

Aspects of the present invention provide, in part, a translocation facilitating domain. As used herein, the term “translocation facilitating domain” means any polypeptide that can further facilitate the translocation step of the intoxication process that mediates Clostridial toxin light chain translocation. Thus, a translocation facilitating domain assists the Clostridial toxin translocation domain in the movement of a Clostridial toxin light chain across a membrane and encompasses the movement of a Clostridial toxin light chain through the membrane of an intracellular vesicle into the cytoplasm of a cell. A non-limiting example of a translocation facilitating domain is a Clostridial toxin translocation facilitating domain, such as, e.g., a Clostridial toxin HCN region such as, e.g., a BoNT/A HCN region, a BoNT/B HCN region, a BoNT/C1 HCN region, a BoNT/D HCN region, a BoNT/E HCN region, a BoNT/F HCN region, a BoNT/G HCN region, and a TeNT HCN region. Another non-limiting example of a translocation facilitating domain is a viral fusogenic peptide domain found in an enveloped virus, such as, e.g., an influenzavirus, an alphavirus, a vesiculovirus, a respirovirus, a morbillivirus, an avulavirus, a henipavirus, a metapneumovirus and a foamy virus.

Thus, in an embodiment, a translocation facilitating domain facilitates the Clostridial toxin translocation domain in the movement of a Clostridial toxin light chain across a membrane. In aspects of this embodiment, a translocation facilitating domain facilitates the Clostridial toxin translocation domain in the movement of a Clostridial toxin light chain across a membrane by increasing the amount of Clostridial toxin light chain in the cytoplasm by, e.g., at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 100%. In other aspects of this embodiment, a translocation facilitating domain facilitates the Clostridial toxin translocation domain in the movement of a Clostridial toxin light chain across a membrane by increasing the amount of Clostridial toxin light chain in the cytoplasm by, e.g., at least two-fold, at least three-fold, at least four-fold, at least five-fold, at least ten-fold or at least twenty-fold. In yet other aspects of this embodiment, a translocation facilitating domain facilitates the Clostridial toxin translocation domain in the movement of a Clostridial toxin light chain across a membrane by increasing the amount of Clostridial toxin light chain in the cytoplasm by, e.g., at most 10%, at most 20%, at most 30%, at most 40%, at most 50%, at most 60%, at most 70%, at most 80%, at most 90% or at most 100%. In other aspects of this embodiment, a translocation facilitating domain facilitates the Clostridial toxin translocation domain in the movement of a Clostridial toxin light chain across a membrane by increasing the amount of Clostridial toxin light chain in the cytoplasm by, e.g., at most two-fold, at most three-fold, at most four-fold, at most five-fold, at most ten-fold or at most twenty-fold.

As used herein, the term “Clostridial toxin HCN region variant,” whether naturally-occurring or non-naturally-occurring, means a Clostridial toxin HCN region that has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 1) and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all Clostridial toxin HCN region variants disclosed in the present specification are capable of further facilitating the translocation step of the intoxication process that mediates Clostridial toxin light chain translocation. As non-limiting examples, a BoNT/A HCN region variant comprising amino acids 874-1110 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 874-1110 of SEQ ID NO: 1; a BoNT/B HCN region variant comprising amino acids 861-1097 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 861-1097 of SEQ ID NO: 2; a BoNT/C1 HCN region variant comprising amino acids 869-1111 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 869-1111 of SEQ ID NO: 3; a BoNT/D HCN region variant comprising amino acids 865-1098 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 865-1098 of SEQ ID NO: 4; a BoNT/E HCN region variant comprising amino acids 848-1085 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 848-1085 of SEQ ID NO: 5; a BoNT/F HCN region variant comprising amino acids 867-1105 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 867-1105 of SEQ ID NO: 6; a BoNT/G HCN region variant comprising amino acids 866-1105 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 866-1105 of SEQ ID NO: 7; and a TeNT HCN region variant comprising amino acids 882-1127 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 882-1127 of SEQ ID NO: 8.

It is recognized by those of skill in the art that within each serotype of Clostridial toxin there can be naturally occurring Clostridial toxin HCN region variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. For example, there are presently four BoNT/A subtypes, BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4, with specific HCN region subtypes showing approximately 87% amino acid identity when compared to another BoNT/A HCN region subtype. As used herein, the term “naturally occurring Clostridial toxin HCN region variant” means any Clostridial toxin HCN region produced by a naturally-occurring process, including, without limitation, Clostridial toxin HCN region isoforms produced from alternatively-spliced transcripts, Clostridial toxin HCN region isoforms produced by spontaneous mutation and Clostridial toxin HCN region subtypes. A naturally occurring Clostridial toxin HCN region variant can function in substantially the same manner as the reference Clostridial toxin HCN region on which the naturally occurring Clostridial toxin HCN region variant is based, and can be substituted for the reference Clostridial toxin HCN region in any aspect of the present invention. A naturally occurring Clostridial toxin HCN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids or 50 or more amino acids from the reference Clostridial toxin HCN region on which the naturally occurring Clostridial toxin HCN region variant is based. A naturally occurring Clostridial toxin HCN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HCN region on which the naturally occurring Clostridial toxin HCN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HCN region on which the naturally occurring Clostridial toxin HCN region variant is based.

A non-limiting examples of a naturally occurring Clostridial toxin HCN region variant is a Clostridial toxin HCN region isoform such as, e.g., a BoNT/A HCN region isoform, a BoNT/B HCN region isoform, a BoNT/C1 HCN region isoform, a BoNT/D HCN region isoform, a BoNT/E HCN region isoform, a BoNT/F HCN region isoform, a BoNT/G HCN region isoform, and a TeNT HCN region isoform. A Clostridial toxin HCN region isoform can function in substantially the same manner as the reference Clostridial toxin HCN region on which the Clostridial toxin HCN region isoform is based, and can be substituted for the reference Clostridial toxin HCN region in any aspect of the present invention.

Another non-limiting examples of a naturally occurring Clostridial toxin HCN region variant is a Clostridial toxin HCN region subtype such as, e.g., a HCN region from subtype BoNT/A1, BoNT/A2, BoNT/A3 and BoNT/A4; a HCN region from subtype BoNT/B1, BoNT/B2, BoNT/B bivalent and BoNT/B nonproteolytic; a HCN region from subtype BoNT/C1-1 and BoNT/C1-2; a HCN region from subtype BoNT/E1, BoNT/E2 and BoNT/E3; and a HCN region from subtype BoNT/F1, BoNT/F2, BoNT/F3 and BoNT/F4. A Clostridial toxin HCN region subtype can function in substantially the same manner as the reference Clostridial toxin HCN region on which the Clostridial toxin HCN region subtype is based, and can be substituted for the reference Clostridial toxin HCN region in any aspect of the present invention.

As used herein, the term “conservative Clostridial toxin HCN region variant” means a Clostridial toxin HCN region that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference Clostridial toxin HCN region sequence (Table 1). Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative Clostridial toxin HCN region variant can function in substantially the same manner as the reference Clostridial toxin HCN region on which the conservative Clostridial toxin HCN region variant is based, and can be substituted for the reference Clostridial toxin HCN region in any aspect of the present invention. A conservative Clostridial toxin HCN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin HCN region on which the conservative Clostridial toxin HCN region variant is based. A conservative Clostridial toxin HCN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HCN region on which the conservative Clostridial toxin HCN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HCN region on which the conservative Clostridial toxin HCN region variant is based. Non-limiting examples of a conservative Clostridial toxin HCN region variant include, e.g., conservative BoNT/A HCN region variants, conservative BoNT/B HCN region variants, conservative BoNT/C1 HCN region variants, conservative BoNT/D HCN region variants, conservative BoNT/E HCN region variants, conservative BoNT/F HCN region variants, conservative BoNT/G HCN region variants, and conservative TeNT HCN region variants.

As used herein, the term “non-conservative Clostridial toxin HCN region variant” means a Clostridial toxin HCN region in which 1) at least one amino acid is deleted from the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region variant is based; 2) at least one amino acid added to the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference Clostridial toxin HCN region sequence (Table 1). A non-conservative Clostridial toxin HCN region variant can function in substantially the same manner as the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region variant is based, and can be substituted for the reference Clostridial toxin HCN region in any aspect of the present invention. A non-conservative Clostridial toxin HCN region variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region variant is based. A non-conservative Clostridial toxin HCN region variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region variant is based. A non-conservative Clostridial toxin HCN region variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region variant is based. A non-conservative Clostridial toxin HCN region variant can also substitute at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference Clostridial toxin HCN region on which the non-conservative Clostridial toxin HCN region variant is based. Non-limiting examples of a non-conservative Clostridial toxin HCN region variant include, e.g., non-conservative BoNT/A HCN region variants, non-conservative BoNT/B HCN region variants, non-conservative BoNT/C1 HCN region variants, non-conservative BoNT/D HCN region variants, non-conservative BoNT/E HCN region variants, non-conservative BoNT/F HCN region variants, non-conservative BoNT/G HCN region variants, and non-conservative TeNT HCN region variants.

As used herein, the term “Clostridial toxin HCN region chimeric” means a polypeptide comprising at least a portion of a Clostridial toxin HCN region and at least a portion of at least one other polypeptide to form a toxin HCN region with at least one property different from the reference Clostridial toxin HCN regions of Table 1, with the proviso that this Clostridial toxin HCN region chimeric is still capable of further facilitating the translocation step of the intoxication process where the LC is released from intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate.

As used herein, the term “active Clostridial toxin HCN region fragment” means any of a variety of Clostridial toxin fragments comprising the HCN region can be useful in aspects of the present invention with the proviso that these active fragments can further facilitate the translocation step of the intoxication process where the LC is released from intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. The HCN domains from the heavy chains of Clostridial toxins are approximately 230-250 amino acids in length and comprise a translocation domain (Table 1). Additionally, while a specific amino acid positions have been identified to delineate the boundaries of the Clostridial toxin HCN region (Table 1), it is well known in the art that the functional boundaries are not definitive. For example, amino-terminus of the HCN domain for all naturally-occurring Clostridial toxins is the HN domain (translocation domain). In examining the structure for BoNT/A, a random coil linker region forms a boundary between the HN and HCN domains (see FIG. 7A). The BoNT/A HN domain appears to end with an α-helix comprising amino acids N859 to 1873. Following the α-helix there is a random coil (1873 to 1878) that leads into the HCN domain where a β-sheet begins at position 1878. The above residues define boundaries at the beginning or end of defined secondary structures and do not imply that there are not significant interactions (i.e., hydrophobic, H-bond, etc.) between residues in the random coil region and one or both of the domains that it links together. Thus, minimally an amino acid that defines the amino-terminal boundary of the BoNT/A HCN domain comprises can be any amino acid present in the amino acid region Y869 to L879. Similar analysis indicates that minimally, the amino acid that defines the amino-terminal boundary of the BoNT/B HCN domain can be any amino acid present in the amino acid region Y856 to L866; the amino acid that defines the amino-terminal boundary of the BoNT/C1 HCN domain can be any amino acid present in the amino acid region Y864 to L874; the amino acid that defines the amino-terminal boundary of the BoNT/D HCN domain can be any amino acid present in the amino acid region Y860 to L870; the amino acid that defines the amino-terminal boundary of the BoNT/E HCN domain can be any amino acid present in the amino acid region F843 to L853; the amino acid that defines the amino-terminal boundary of the BoNT/F HCN domain can be any amino acid present in the amino acid region L862 to L872; the amino acid that defines the amino-terminal boundary of the BoNT/G HCN domain can be any amino acid present in the amino acid region Y861 to L871; and the amino acid that defines the amino-terminal boundary of the TeNT HCN domain can be any amino acid present in the amino acid region 1877 to L887.

Similarly, the carboxyl-terminal portion of the HCN domain (i.e., the fusion point between the HCN and HCC domains) all naturally-occurring Clostridial toxins comprises a range of amino acids. In defining the boundary of the BoNT/A HCN domain as the beginning or the end of ordered secondary structure, the HCN domain could end at Q1091 of an α-helix and the HCC domain could begin at K1109 of a β-strand (see FIG. 7B). The intervening amino acid sequence between these two domains comprises a longer random coil but, this does not imply that the random coil is not structurally important. In fact, this random coil has a great deal of interaction with both the HCN and HCC domains (i.e., hydrophobic and H-bonding). Thus, minimally an amino acid that defines the carboxyl-terminal boundary of the BoNT/A HCN domain comprises can be any amino acid present in the amino acid region D1089 to Y1111. Similar analysis indicates that minimally, the amino acid that defines the carboxyl-terminal boundary of the BoNT/B HCN domain can be any amino acid present in the amino acid region K1076 to Y1098; the amino acid that defines the carboxyl-terminal boundary of the BoNT/C1 HCN domain can be any amino acid present in the amino acid region N1090 to Y1112; the amino acid that defines the carboxyl-terminal boundary of the BoNT/D HCN domain can be any amino acid present in the amino acid region E1077 to Y1099; the amino acid that defines the carboxyl-terminal boundary of the BoNT/E HCN domain can be any amino acid present in the amino acid region S1064 to Y1086; the amino acid that defines the carboxyl-terminal boundary of the BoNT/F HCN domain can be any amino acid present in the amino acid region S1084 to Y1106; the amino acid that defines the carboxyl-terminal boundary of the BoNT/G HCN domain can be any amino acid present in the amino acid region W1084 to Y1106; and the amino acid that defines the carboxyl-terminal boundary of the TeNT HCN domain can be any amino acid present in the amino acid region T1106 to Y1128.

Thus, aspects of this embodiment can include Clostridial toxin HCN regions comprising a translocation facilitating domain having a length of, e.g., at least 200 amino acids, at least 225 amino acids, at least 250 amino acids and at least 275 amino acids. Other aspects of this embodiment can include Clostridial toxin HCN regions comprising translocation facilitating domain having a length of, e.g., at most 200 amino acids, at most 225 amino acids, at most 250 amino acids and at most 275 amino acids.

Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring Clostridial toxin HCN region variants and non-naturally-occurring Clostridial toxin HCN region variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein.

The fusion of the membrane of enveloped viruses to a cellular membrane is an essential step in the release of the viral capsule into the cytoplasm of the host cell. This fusion event is mediated by a fusogenic peptide segment present in viral glycoproteins located on the viral membrane and involves either a pH-dependent or pH-independent process, see, e.g., Frederick M. Hughson, Structural Characterization of Viral Fusion Proteins, 5(3) Curr. Biol. 189-274 (1159); Trudy G. Morrison, Structure and Function of a Paramyxovirus Fusion Protein, 1614(1) Biochim. Biophys. Acta. 73-84; David J. Schibli and Winfried Weissenhorn, Class I and Class II Viral Fusion Protein Structures Reveal Similar Principles in Membrane Fusion, 21(6) Mol. Membr. Biol. 361-371 (1168). The fusogenic peptide domain comprises a hydrophobic, glycine-rich peptide of approximately 20-30 amino acids that assist in the insertion of the viral capsule into a cellular membrane. Thus, an enveloped virus fusogenic peptide domain can be useful as a translocation facilitating domain.

As used herein, the term “non-conservative enveloped virus fusogenic peptide domain variant” means an enveloped virus fusogenic peptide domain in which 1) at least one amino acid is deleted from the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain variant is based; 2) at least one amino acid added to the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference enveloped virus fusogenic peptide domain sequence. A non-conservative enveloped virus fusogenic peptide domain variant can function in substantially the same manner as the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain variant is based, and can be substituted for the reference enveloped virus fusogenic peptide domain in any aspect of the present invention. A non-conservative enveloped virus fusogenic peptide domain variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids or five or more amino acids from the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain variant is based. A non-conservative enveloped virus fusogenic peptide domain variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids or five or more amino acids to the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain variant is based. A non-conservative enveloped virus fusogenic peptide domain variant may substitute one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids or ten or more amino acids from the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain variant is based. A non-conservative enveloped virus fusogenic peptide domain variant can also substitute at least 2 contiguous amino acids, at least 3 contiguous amino acids, at least 4 contiguous amino acids or at least 5 contiguous amino acids from the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference enveloped virus fusogenic peptide domain on which the non-conservative enveloped virus fusogenic peptide domain variant is based. Non-limiting examples of a non-conservative enveloped virus fusogenic peptide domain variant include, e.g., non-conservative influenzavirus fusogenic peptide domain variants, non-conservative alphavirus fusogenic peptide domain variants, non-conservative vesiculovirus fusogenic peptide domain variants, non-conservative respirovirus fusogenic peptide domain variants, non-conservative morbillivirus fusogenic peptide domain variants, non-conservative avulavirus fusogenic peptide domain variants, non-conservative henipavirus fusogenic peptide domain variants, non-conservative metapneumovirus fusogenic peptide domain variants and non-conservative foamy virus fusogenic peptide domain variants.

As used herein, the term “enveloped virus fusogenic peptide domain chimeric” means a polypeptide comprising at least a portion of an enveloped virus fusogenic peptide domain and at least a portion of at least one other polypeptide to form an enveloped virus fusogenic peptide domain with at least one property different from the reference enveloped virus fusogenic peptide domain, with the proviso that this enveloped virus fusogenic peptide domain chimeric is still capable of further facilitating the translocation step of the intoxication process where the LC is released from intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate.

As used herein, the term “active enveloped virus fusogenic peptide domain fragment” means any of a variety of enveloped virus fusogenic peptide domain fragments that can further facilitate the translocation step of the intoxication process where the LC is released from intracellular vesicles into the cytoplasm of the target cell and thus participate in executing the overall cellular mechanism whereby a Clostridial toxin proteolytically cleaves a substrate. Enveloped virus fusogenic peptide domains are approximately 15-30 amino acids in length. Thus, aspects of this embodiment can include a translocation facilitating domain comprising an active enveloped virus fusogenic peptide domain fragment having a length of, e.g., at least 10 amino acids, at least 15 amino acids, at least 20 amino acids and at least 25 amino acids. Other aspects of this embodiment can include a translocation facilitating domain comprising an active enveloped virus fusogenic peptide domain fragment having a length of, e.g., at most 10 amino acids, at most 15 amino acids, at most 20 amino acids and at most 25 amino acids.

Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring enveloped virus fusogenic peptide domain variants and non-naturally-occurring enveloped virus fusogenic peptide domain variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein.

Aspects of the present invention provide, in part, an altered targeting domain. As used herein, the term “altered targeting domain” means any polypeptide that can selectively bind to a non-Clostridial toxin receptor present on a non-Clostridial toxin target cell and initiate the overall internalization mechanism whereby the modified Clostridial toxin disclosed in the present specification intoxicates a target cell. As used herein, the term “selectively” means having a highly preferred activity or effect. As used herein, the term “selectively bind” means a molecule is able to bind its target receptor under physiological conditions, or in vitro conditions substantially approximating physiological conditions, to a statistically significantly greater degree relative to other, non-target receptors. Thus, with reference to an altered targeting domain of the present specification, there is a discriminatory binding of the altered targeting domain to a non-Clostridial toxin receptor presence in a non-Clostridial toxin target cell.

Aspects of the present invention provide, in part, an altered targeting domain. As used herein, the term “altered targeting domain” means any polypeptide that can selectively bind to a non-Clostridial toxin receptor present on a Clostridial toxin target cell and initiate the overall internalization mechanism whereby the modified Clostridial toxin disclosed in the present specification intoxicates a target cell. As used herein, the term “selectively” means having a highly preferred activity or effect. As used herein, the term “selectively bind” means a molecule is able to bind its target receptor under physiological conditions, or in vitro conditions substantially approximating physiological conditions, to a statistically significantly greater degree relative to other, non-target receptors. Thus, with reference to an altered targeting domain of the present specification, there is a discriminatory binding of the altered targeting domain to a non-Clostridial toxin receptor present in a Clostridila toxin target cell.

An altered targeting domain disclosed in the present specification facilitates the binding activity of the modified Clostridial toxins disclosed in the present specification to a non-Clostridial toxin receptor located at the surface of a Clostridial toxin target cell. As used herein, the term “binding activity” means that one molecule is directly or indirectly contacting another molecule via at least one intermolecular or intramolecular force, including, without limitation, a covalent bond, an ionic bond, a metallic bond, a hydrogen bond, a hydrophobic interaction, a van der Waals interaction, and the like, or any combination thereof. “Bound” and “bind” are considered terms for binding.

As used herein, the term “binding affinity” means how strong a molecule's binding activity is for a particular receptor. In general, high binding affinity results from greater intermolecular force between a binding domain and its receptor while low binding affinity involves less intermolecular force between the ligand and its receptor. High binding affinity involves a longer residence time for the binding domain at its receptor binding site than is the case for low binding affinity. As such, a molecule with a high binding affinity means a lower concentration of that molecule is required to maximally occupy the binding sites of a receptor and trigger a physiological response. Conversely, low binding affinity means a relatively high concentration of a molecule is required before the receptor binding sites of a receptor is maximally occupied and the maximum physiological response is achieved. Thus, modified Clostridial toxins with increased binding activity due to high binding affinity will allow administration of reduced doses of the toxin, thereby reducing or preventing unwanted side-effects associated with toxin dispersal into non-targeted areas.

As used herein, the term “binding specificity” means how specific a molecule's binding activity is one particular receptor. In general, high binding specificity results in a more exclusive interaction with one particular receptor or subgroup of receptors while low binding specificity results in a more promiscuous interaction with a larger group of receptors. As such, a molecule with a high binding specificity means that molecule will occupy the binding sites of a particular receptor and trigger a physiological response. Conversely, low binding specificity means a molecule will occupy the binding sites of a many receptors and trigger a multitude of physiological responses. Thus, modified Clostridial toxins with increased binding activity due to high binding specificity will only target non-Clostridial toxin receptors present on a subgroup of Clostridial toxin target cells, thereby reducing the side effects associated with the targeting of all Clostridial toxin target cells.

In addition to its altered targeting activity, replacement of a naturally-occurring targeting domain with an altered target domain disclosed in the specification has an added advantage of reducing the likelihood of the modified toxin from eliciting an immunogenic response. Regions found in the HCC targeting domain are bound by neutralizing anti-BoNT/A antibodies, see, e.g., M. Zouhair Atassi et al., Mapping of the Antibody-binding Regions on Botulinum Neurotoxin H-chain Domain 855-1296 with Anti-toxin Antibodies from Three Host Species, 15 J. PROT. CHEM. 691-700, (1996); M. Zouhair Atassi & Behzod Z. Dolimbek, Mapping of the Antibody-binding Profile on Botulinum Neurotoxin A HN-domain (residues 449-859) with Anti-toxin Antibodies from Four Host Species. Antigenic Profile of the Entire H-chain of Botulinum Neurotoxin A, 23(1) PROTEIN J. 39-52, (2004). Therefore, elimination of this targeting domain will reduce the likelihood of an immunogenic response because 1) the Clostridial toxin HCC targeting domain is absent; 2) an altered targeting domain derived from a human will most likely not elicit an immunogenic response in a patient because it is a human polypeptide.

As used herein, the term “variant,” when used to describe an altered targeting domain variant, whether naturally-occurring or non-naturally-occurring, means an altered targeting domain that has at least one amino acid change from the corresponding region of the disclosed reference sequences and can be described in percent identity to the corresponding region of that reference sequence. Unless expressly indicated, all altered targeting domain variants disclosed in the present specification are capable of selectively binding to a non-Clostridial toxin receptor present on a Clostridial toxin target cell and initiate the overall internalization mechanism whereby the modified Clostridial toxin disclosed in the present specification intoxicates a target cell. As non-limiting examples, a glycogen-like peptide variant derived from amino acids 21-50 of SEQ ID NO: 9 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 21-50 of SEQ ID NO: 9; a PACAP variant derived from amino acids 132-158 of SEQ ID NO: 10 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 132-158 of SEQ ID NO: 10; a CCRH variant derived from amino acids 159-193 of SEQ ID NO: 19 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 159-193 of SEQ ID NO: 19; a PTH variant derived from amino acids 35-70 of SEQ ID NO: 20 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 35-70 of SEQ ID NO: 20; an IL-6 variant derived from amino acids 57-210 of SEQ ID NO: 28 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 57-210 of SEQ ID NO: 28; a neuroleukin variant derived from amino acids 54-546 of SEQ ID NO: 31 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 54-546 of SEQ ID NO: 31; an IGF-1 variant derived from amino acids 52-109 of SEQ ID NO: 33 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 52-109 of SEQ ID NO: 33; and a NT-3 variant derived from amino acids 144-249 of SEQ ID NO: 38 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 144-249 of SEQ ID NO: 38.

It is recognized by those of skill in the art that there can be naturally occurring altered targeting domain variants that differ somewhat in their amino acid sequence, and also in the nucleic acids encoding these proteins. As used herein, the term “naturally occurring altered targeting domain variant” means any altered targeting domain produced by a naturally-occurring process, including, without limitation, altered targeting domain isoforms produced from alternatively-spliced transcripts, altered targeting domain isoforms produced by spontaneous mutation and altered targeting domain subtypes. A naturally occurring altered targeting domain variant can function in substantially the same manner as the reference altered targeting domain on which the naturally occurring altered targeting domain variant is based, and can be substituted for the reference altered targeting domain in any aspect of the present invention. A naturally occurring altered targeting domain variant may substitute, e.g., one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids or 100 or more amino acids from the reference altered targeting domain on which the naturally occurring altered targeting domain variant is based. A naturally occurring altered targeting domain variant can also substitute, e.g., at least 5 contiguous amino acids, at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference altered targeting domain on which the naturally occurring altered targeting domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference altered targeting domain on which the naturally occurring altered targeting domain variant is based.

A non-limiting example of a naturally occurring altered targeting domain variant is an altered targeting domain isoform such as, e.g., a glucogen-like peptide isoform, a PACAP isoform, a CCRH isoform, a PTH isoform, an IL-6 isoform, a neuroleukin isoform, an IGF-1 isoform, and a NT-3 isoform. An altered targeting domain isoform can function in substantially the same manner as the reference altered targeting domain on which the altered targeting domain isoform is based, and can be substituted for the reference altered targeting domain in any aspect of the present invention.

As used herein, the term “conservative altered targeting domain variant” means an altered targeting domain that has at least one amino acid substituted by another amino acid or an amino acid analog that has at least one property similar to that of the original amino acid from the reference altered targeting domain sequence. Examples of properties include, without limitation, similar size, topography, charge, hydrophobicity, hydrophilicity, lipophilicity, covalent-bonding capacity, hydrogen-bonding capacity, a physicochemical property, of the like, or any combination thereof. A conservative altered targeting domain variant can function in substantially the same manner as the reference altered targeting domain on which the conservative altered targeting domain variant is based, and can be substituted for the reference altered targeting domain in any aspect of the present invention. A conservative altered targeting domain variant may substitute, e.g., one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference altered targeting domain on which the conservative altered targeting domain variant is based. A conservative altered targeting domain variant can also substitute, e.g., at least 5 contiguous amino acids, at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference altered targeting domain on which the conservative altered targeting domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference altered targeting domain on which the conservative altered targeting domain variant is based. Non-limiting examples of a conservative altered targeting domain variant include, e.g., conservative glucogen-like peptide variants, conservative PACAP region variants, conservative CCRH region variants, conservative PTH variants, conservative IL-6 variants, conservative neuroleukin variants, conservative IGF-1 variants, and conservative NT-3 region variants.

As used herein, the term “non-conservative altered targeting domain variant” means an altered targeting domain in which 1) at least one amino acid is deleted from the reference altered targeting domain on which the non-conservative altered targeting domain variant is based; 2) at least one amino acid added to the reference altered targeting domain on which the non-conservative altered targeting domain is based; or 3) at least one amino acid is substituted by another amino acid or an amino acid analog that does not share any property similar to that of the original amino acid from the reference altered targeting domain sequence. A non-conservative altered targeting domain variant can function in substantially the same manner as the reference altered targeting domain on which the non-conservative altered targeting domain variant is based, and can be substituted for the reference altered targeting domain in any aspect of the present invention. A non-conservative altered targeting domain variant can delete one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids from the reference altered targeting domain on which the non-conservative altered targeting domain variant is based. A non-conservative altered targeting domain variant can add one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, and ten or more amino acids to the reference altered targeting domain on which the non-conservative altered targeting domain variant is based. A non-conservative altered targeting domain variant may substitute, e.g., one or more amino acids, two or more amino acids, three or more amino acids, four or more amino acids, five or more amino acids, ten or more amino acids, 20 or more amino acids, 30 or more amino acids, 40 or more amino acids, 50 or more amino acids, 100 or more amino acids, 200 or more amino acids, 300 or more amino acids, 400 or more amino acids, or 500 or more amino acids from the reference altered targeting domain on which the non-conservative altered targeting domain variant is based. A non-conservative altered targeting domain variant can also substitute, e.g., at least 5 contiguous amino acids, at least 10 contiguous amino acids, at least 15 contiguous amino acids, at least 20 contiguous amino acids, or at least 25 contiguous amino acids from the reference altered targeting domain on which the non-conservative altered targeting domain variant is based, that possess at least 50% amino acid identity, 65% amino acid identity, 75% amino acid identity, 85% amino acid identity or 95% amino acid identity to the reference altered targeting domain on which the non-conservative altered targeting domain variant is based. Non-limiting examples of a non-conservative altered targeting domain variant include, e.g., non-conservative glucogen-like peptide variants, non-conservative PACAP region variants, non-conservative CCRH region variants, non-conservative PTH variants, non-conservative IL-6 variants, non-conservative neuroleukin variants, non-conservative IGF-1 variants, and non-conservative NT-3 region variants.

As used herein, the term “altered targeting domain chimeric” means a polypeptide comprising at least a portion of an altered targeting domain and at least a portion of at least one other polypeptide to form an altered targeting domain with at least one property different from the reference altered targeting domain, with the proviso that this altered targeting domain chimeric is still capable of selectively binding to a non-Clostridial toxin receptor present on a Clostridial toxin target cell and initiate the overall internalization mechanism whereby a modified Clostridial toxin intoxicates a target cell.

As used herein, the term “active altered targeting domain fragment” means any of a variety of altered targeting domain fragments can be useful in aspects of the present invention with the proviso that these active fragments are still capable of selectively binding to a non-Clostridial toxin receptor present on a Clostridial toxin target cell and initiate the overall internalization mechanism whereby a Clostridial toxin intoxicates a target cell. Thus, aspects of this embodiment can include altered targeting domains comprising a length of, e.g., at least 5 amino acids, at least 10 amino acids, at least 20 amino acids, at least 30 amino acids, at least 40 amino acids, at least 50 amino acids, at least 100 amino acids, at least 150 amino acids, at least 200 amino acids, at least 250 amino acids, at least 300 amino acids, at least 350 amino acids, at least 400 amino acids and at least 450 amino acids. Other aspects of this embodiment can include altered targeting domains comprising a length of, e.g., at most 5 amino acids, at most 10 amino acids, at most 20 amino acids, at most 30 amino acids, at most 40 amino acids, at most 50 amino acids, at most 100 amino acids, at most 150 amino acids, at most 200 amino acids, at most 250 amino acids, at most 300 amino acids, at most 350 amino acids, at most 400 amino acids and at most 450 amino acids.

Any of a variety of sequence alignment methods can be used to determine percent identity of naturally-occurring altered targeting domain variants and non-naturally-occurring altered targeting domain variants, including, without limitation, global methods, local methods and hybrid methods, such as, e.g., segment approach methods. Protocols to determine percent identity are routine procedures within the scope of one skilled in the art and from the teaching herein.

Thus, in an embodiment, an altered targeting domain is derived from a glycogen-like peptide. In another embodiment, an altered targeting domain is derived from a glycogen-like peptide of SEQ ID NO: 9. In aspects of this embodiment, an altered targeting domain is derived from a glycogen-like peptide comprises a GRPP, a GLP-1, a GLP-2, a glucagon or an oxyntomodulin. In aspects of this embodiment, an altered targeting domain is derived from a glycogen-like peptide comprising amino acids 21-50, amino acids 53-81, amino acids 53-89, amino acids 98-124, or amino acids 146-178 of SEQ ID NO: 9.

In another embodiment, an altered targeting domain is derived from a PACAP. In another embodiment, an altered targeting domain is derived from a PACAP of SEQ ID NO: 10. In an aspect of this embodiment, an altered targeting domain is derived from a PACAP comprising amino acids 132-158 of SEQ ID NO: 10.

In another embodiment, an altered targeting domain is derived from a GHRH. In another embodiment, an altered targeting domain is derived from a GHRH of SEQ ID NO: 11. In aspects of this embodiment, an altered targeting domain is derived from a GHRH comprising amino acids 32-58 or amino acids 32-75 of SEQ ID NO: 11.

In another embodiment, an altered targeting domain is derived from a VIP1. In another embodiment, an altered targeting domain is derived from a VIP1 of SEQ ID NO: 12. In aspects of this embodiment, an altered targeting domain is derived from a VIP1 comprising amino acids 81-107 or amino acids 125-151 of SEQ ID NO: 12.

In another embodiment, an altered targeting domain is derived from a VIP2. In another embodiment, an altered targeting domain is derived from a VIP2 of SEQ ID NO: 13. In aspects of this embodiment, an altered targeting domain is derived from a VIP2 comprising amino acids 81-107 or amino acids 124-150 of SEQ ID NO: 13.

In another embodiment, an altered targeting domain is derived from a GIP. In another embodiment, an altered targeting domain is derived from a GIP of SEQ ID NO: 14. In aspects of this embodiment, an altered targeting domain is derived from a GIP comprising amino acids 52-78 or amino acids 52-93 of SEQ ID NO: 14.

In another embodiment, an altered targeting domain is derived from a Secretin. In another embodiment, an altered targeting domain is derived from a Secretin of SEQ ID NO: 15. In an aspect of this embodiment, an altered targeting domain is derived from a Secretin comprising amino acids 28-54 of SEQ ID NO: 15.

In another embodiment, an altered targeting domain is derived from a Gastrin. In another embodiment, an altered targeting domain is derived from a Gastrin of SEQ ID NO: 16. In aspects of this embodiment, an altered targeting domain is derived from a Gastrin comprising amino acids 76-92 or amino acids 59-92 of SEQ ID NO: 16.

In another embodiment, an altered targeting domain is derived from a GRP. In another embodiment, an altered targeting domain is derived from a GRP of SEQ ID NO: 17. In aspects of this embodiment, an altered targeting domain is derived from a GRP comprising amino acids 41-50 or amino acids 24-50 of SEQ ID NO: 17.

In another embodiment, an altered targeting domain is derived from a CCK. In another embodiment, an altered targeting domain is derived from a CCK of SEQ ID NO: 18. In an aspect of this embodiment, an altered targeting domain is derived from a CCK comprising amino acids 99-112 of SEQ ID NO: 18.

Thus, in an embodiment, an altered targeting domain is derived from a CCRH. In another embodiment, an altered targeting domain is derived from a CCRH of SEQ ID NO: 19. In aspects of this embodiment, an altered targeting domain is derived from a CCRH comprising amino acids 159-193 or amino acids 154-194 of SEQ ID NO: 19.

In another embodiment, an altered targeting domain is derived from a PTH. In another embodiment, an altered targeting domain is derived from a PTH of SEQ ID NO: 20. In aspects of this embodiment, an altered targeting domain is derived from a PTH comprising amino acids 35-70 or amino acids 145-177 of SEQ ID NO: 20.

Thus, in an embodiment, an altered targeting domain is derived from a CNTF. In another embodiment, an altered targeting domain is derived from a CNTF of SEQ ID NO: 21. In aspects of this embodiment, a CNTF comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 21 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 21. In yet other aspects of this embodiment, a CNTF comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 21, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 21 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 21.

In another embodiment, an altered targeting domain is derived from a GPA. In another embodiment, an altered targeting domain is derived from a GPA of SEQ ID NO: 22. In aspects of this embodiment, a GPA comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 22 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 22. In yet other aspects of this embodiment, a GPA comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 22, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 22 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 22.

In another embodiment, an altered targeting domain is derived from a LIF. In another embodiment, an altered targeting domain is derived from a LIF of SEQ ID NO: 23. In aspects of this embodiment, a LIF comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 23 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 23. In yet other aspects of this embodiment, a LIF comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 23, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 23 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 23.

In another embodiment, an altered targeting domain is derived from a CT-1. In another embodiment, an altered targeting domain is derived from a CT-1 of SEQ ID NO: 24. In aspects of this embodiment, a CT-1 comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 24 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 24. In yet other aspects of this embodiment, a CT-1 comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 24, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 24 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 24.

In another embodiment, an altered targeting domain is derived from a CLC. In another embodiment, an altered targeting domain is derived from a CLC of SEQ ID NO: 25. In aspects of this embodiment, a CLC comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 25 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 25. In yet other aspects of this embodiment, a CLC comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 25, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 25 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 25.

In another embodiment, an altered targeting domain is derived from an IL-1. In another embodiment, an altered targeting domain is derived from an IL-1 of SEQ ID NO: 26. In an aspect of this embodiment, an altered targeting domain is derived from an IL-1 comprising amino acids 123-265 of SEQ ID NO: 26.

In another embodiment, an altered targeting domain is derived from an IL-2. In another embodiment, an altered targeting domain is derived from an IL-2 of SEQ ID NO: 27. In an aspect of this embodiment, an altered targeting domain is derived from an IL-2 comprising amino acids 21-153 of SEQ ID NO: 27.

In another embodiment, an altered targeting domain is derived from an IL-6. In another embodiment, an altered targeting domain is derived from an IL-6 of SEQ ID NO: 28. In an aspect of this embodiment, an altered targeting domain is derived from an IL-6 comprising amino acids 57-210 of SEQ ID NO: 28.

In another embodiment, an altered targeting domain is derived from an IL-8. In another embodiment, an altered targeting domain is derived from an IL-8 of SEQ ID NO: 29. In an aspect of this embodiment, an altered targeting domain is derived from an IL-8 comprising amino acids 21-99 or amino acids 31-94 of SEQ ID NO: 29.

In another embodiment, an altered targeting domain is derived from an IL-10. In another embodiment, an altered targeting domain is derived from an IL-10 of SEQ ID NO: 30. In an aspect of this embodiment, an altered targeting domain is derived from an IL-10 comprising amino acids 37-173 or amino acids 19-178 of SEQ ID NO: 30.

In another embodiment, an altered targeting domain is derived from a neuroleukin. In another embodiment, an altered targeting domain is derived from a neuroleukin of SEQ ID NO: 31. In aspects of this embodiment, a neuroleukin comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 31 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 31. In yet other aspects of this embodiment, a neuroleukin comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 31, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 31 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 31.

In another embodiment, an altered targeting domain is derived from a VEGF. In another embodiment, an altered targeting domain is derived from a VEGF of SEQ ID NO: 32. In aspects of this embodiment, a VEGF comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 32 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 32. In yet other aspects of this embodiment, a VEGF comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 32, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 32 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 32.

In another embodiment, an altered targeting domain is derived from an IGF-1. In another embodiment, an altered targeting domain is derived from an IGF-1 of SEQ ID NO: 33. In an aspect of this embodiment, an altered targeting domain is derived from an IGF-1 comprising amino acids 52-109 or amino acids 49-118 of SEQ ID NO: 33.

In another embodiment, an altered targeting domain is derived from an IGF-2. In another embodiment, an altered targeting domain is derived from an IGF-2 of SEQ ID NO: 34. In an aspect of this embodiment, an altered targeting domain is derived from an IGF-2 comprising amino acids 31-84 or amino acids 25-180 of SEQ ID NO: 34.

In another embodiment, an altered targeting domain is derived from an EGF. In another embodiment, an altered targeting domain is derived from an EGF of SEQ ID NO: 35. In aspects of this embodiment, an EGF comprises a polypeptide having, e.g., at least 70% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at least 75% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at least 80% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at least 85% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at least 90% amino acid identity with the amino acid sequence of SEQ ID NO: 35 or at least 95% amino acid identity with the amino acid sequence of SEQ ID NO: 35. In yet other aspects of this embodiment, an EGF comprises a polypeptide having, e.g., at most 70% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at most 75% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at most 80% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at most 85% amino acid identity with the amino acid sequence of SEQ ID NO: 35, at most 90% amino acid identity with the amino acid sequence of SEQ ID NO: 35 or at most 95% amino acid identity with the amino acid sequence of SEQ ID NO: 35.

Another example of an altered targeting domain disclosed in the present specification is, e.g., a neurotrophin, such as, e.g., a NGF, a BDNF, a NT-3 or a NT-5.

Thus, in an embodiment, an altered targeting domain is derived from a NGF. In another embodiment, an altered targeting domain is derived from a NGF of SEQ ID NO: 36. In an aspect of this embodiment, an altered targeting domain is derived from a NGF comprising amino acids 139-257 of SEQ ID NO: 36.

In another embodiment, an altered targeting domain is derived from a BDGF. In another embodiment, an altered targeting domain is derived from a BDGF of SEQ ID NO: 37. In an aspect of this embodiment, an altered targeting domain is derived from a BDGF comprising amino acids 133-240 or amino acids 129-247 of SEQ ID NO: 37.

In another embodiment, an altered targeting domain is derived from a NT-3. In another embodiment, an altered targeting domain is derived from a NT-3 of SEQ ID NO: 38. In an aspect of this embodiment, an altered targeting domain is derived from a NT-3 comprising amino acids 144-249 or amino acids 19-257 of SEQ ID NO: 38.

In another embodiment, an altered targeting domain is derived from a NT-4/5. In another embodiment, an altered targeting domain is derived from a NT-4/5 of SEQ ID NO: 39. In an aspect of this embodiment, an altered targeting domain is derived from a NT-4/5 comprising amino acids 89-202 or amino acids 81-210 of SEQ ID NO: 39.

Another example of an altered targeting domain disclosed in the present specification is, e.g., a GDNF, a neurturin, a persephrin or an artemin.

Thus, in an embodiment, an altered targeting domain is derived from a GDNF. In another embodiment, an altered targeting domain is derived from a GDNF of SEQ ID NO: 40. In an aspect of this embodiment, an altered targeting domain is derived from a GDNF comprising amino acids 118-211 of SEQ ID NO: 40.

In another embodiment, an altered targeting domain is derived from a Neurturin. In another embodiment, an altered targeting domain is derived from a Neurturin of SEQ ID NO: 41. In an aspect of this embodiment, an altered targeting domain is derived from a Neurturin comprising amino acids 107-196 or amino acids 96-197 of SEQ ID NO: 41.

In another embodiment, an altered targeting domain is derived from a Persephrin. In another embodiment, an altered targeting domain is derived from a Persephrin of SEQ ID NO: 42. In an aspect of this embodiment, an altered targeting domain is derived from a Persephrin comprising amino acids 66-155 of SEQ ID NO: 42.

In another embodiment, an altered targeting domain is derived from an Artemin. In another embodiment, an altered targeting domain is derived from an Artemin of SEQ ID NO: 43. In an aspect of this embodiment, an altered targeting domain is derived from an Artemin comprising amino acids 123-218 of SEQ ID NO: 43.

Another example of an altered targeting domain disclosed in the present specification is, e.g., a TGFβs, such as, e.g., TGFβ1, TGFβ2, TGFβ3 or TGFβ4.

Thus, in an embodiment, an altered targeting domain is derived from a TGFβ1. In another embodiment, an altered targeting domain is derived from a TGFβ1 of SEQ ID NO: 44. In an aspect of this embodiment, an altered targeting domain is derived from a TGFβ1 comprising amino acids 293-390 of SEQ ID NO: 44.

In another embodiment, an altered targeting domain is derived from a TGFβ2. In another embodiment, an altered targeting domain is derived from a TGFβ2 of SEQ ID NO: 44. In an aspect of this embodiment, an altered targeting domain is derived from a TGFβ2 comprising amino acids 317-414 of SEQ ID NO: 45.

In another embodiment, an altered targeting domain is derived from a TGFβ3. In another embodiment, an altered targeting domain is derived from a TGFβ3 of SEQ ID NO: 44. In an aspect of this embodiment, an altered targeting domain is derived from a TGFβ3 comprising amino acids 315-412 of SEQ ID NO: 46.

In another embodiment, an altered targeting domain is derived from a TGFβ4. In another embodiment, an altered targeting domain is derived from a TGFβ4 of SEQ ID NO: 44. In an aspect of this embodiment, an altered targeting domain is derived from a TGFβ4 comprising amino acids 276-373 of SEQ ID NO: 47.

Thus, in an embodiment, an altered targeting domain is derived from a BMP2. In another embodiment, an altered targeting domain is derived from a BMP2 of SEQ ID NO: 48. In an aspect of this embodiment, an altered targeting domain is derived from a BMP2 comprising amino acids 296-396 of SEQ ID NO: 48.

In another embodiment, an altered targeting domain is derived from a BMP3. In another embodiment, an altered targeting domain is derived from a BMP3 of SEQ ID NO: 49. In an aspect of this embodiment, an altered targeting domain is derived from a BMP3 comprising amino acids 370-472 of SEQ ID NO: 49.

In another embodiment, an altered targeting domain is derived from a BMP4. In another embodiment, an altered targeting domain is derived from a BMP4 of SEQ ID NO: 50. In an aspect of this embodiment, an altered targeting domain is derived from a BMP4 comprising amino acids 309-409 of SEQ ID NO: 50.

In another embodiment, an altered targeting domain is derived from a BMP5. In another embodiment, an altered targeting domain is derived from a BMP5 of SEQ ID NO: 51. In an aspect of this embodiment, an altered targeting domain is derived from a BMP5 comprising amino acids 353-454 or amino acids 323-454 of SEQ ID NO: 51.

In another embodiment, an altered targeting domain is derived from a BMP6. In another embodiment, an altered targeting domain is derived from a BMP6 of SEQ ID NO: 52. In an aspect of this embodiment, an altered targeting domain is derived from a BMP6 comprising amino acids 412-513 or amino acids 374-513 of SEQ ID NO: 52.

In another embodiment, an altered targeting domain is derived from a BMP7. In another embodiment, an altered targeting domain is derived from a BMP7 of SEQ ID NO: 53. In an aspect of this embodiment, an altered targeting domain is derived from a BMP7 comprising amino acids 330-431 or amino acids 293-431 of SEQ ID NO: 53.

In another embodiment, an altered targeting domain is derived from a BMP8. In another embodiment, an altered targeting domain is derived from a BMP8 of SEQ ID NO: 54. In an aspect of this embodiment, an altered targeting domain is derived from a BMP8 comprising amino acids 301-402 of SEQ ID NO: 54.

In another embodiment, an altered targeting domain is derived from a BMP10. In another embodiment, an altered targeting domain is derived from a BMP10 of SEQ ID NO: 55. In an aspect of this embodiment, an altered targeting domain is derived from a BMP10 comprising amino acids 323-424 of SEQ ID NO: 55.

Thus, in an embodiment, an altered targeting domain is derived from a GDF1. In another embodiment, an altered targeting domain is derived from a GDF1 of SEQ ID NO: 56. In an aspect of this embodiment, an altered targeting domain is derived from a GDF1 comprising amino acids 267-372 of SEQ ID NO: 56.

In another embodiment, an altered targeting domain is derived from a GDF2. In another embodiment, an altered targeting domain is derived from a GDF2 of SEQ ID NO: 57. In an aspect of this embodiment, an altered targeting domain is derived from a GDF2 comprising amino acids 327-429 of SEQ ID NO: 57.

In another embodiment, an altered targeting domain is derived from a GDF3. In another embodiment, an altered targeting domain is derived from a GDF3 of SEQ ID NO: 58. In an aspect of this embodiment, an altered targeting domain is derived from a GDF3 comprising amino acids 264-364 of SEQ ID NO: 58.

In another embodiment, an altered targeting domain is derived from a GDF5. In another embodiment, an altered targeting domain is derived from a GDF5 of SEQ ID NO: 59. In an aspect of this embodiment, an altered targeting domain is derived from a GDF5 comprising amino acids 400-501 of SEQ ID NO: 59.

In another embodiment, an altered targeting domain is derived from a GDF6. In another embodiment, an altered targeting domain is derived from a GDF6 of SEQ ID NO: 60. In an aspect of this embodiment, an altered targeting domain is derived from a GDF6 comprising amino acids 354-455 of SEQ ID NO: 60.

In another embodiment, an altered targeting domain is derived from a GDF7. In another embodiment, an altered targeting domain is derived from a GDF7 of SEQ ID NO: 61. In an aspect of this embodiment, an altered targeting domain is derived from a GDF7 comprising amino acids 352-450 of SEQ ID NO: 61.

In another embodiment, an altered targeting domain is derived from a GDF8. In another embodiment, an altered targeting domain is derived from a GDF8 of SEQ ID NO: 62. In an aspect of this embodiment, an altered targeting domain is derived from a GDF8 comprising amino acids 281-375 of SEQ ID NO: 62.

In another embodiment, an altered targeting domain is derived from a GDF10. In another embodiment, an altered targeting domain is derived from a GDF10 of SEQ ID NO: 63. In an aspect of this embodiment, an altered targeting domain is derived from a GDF10 comprising amino acids 376-478 of SEQ ID NO: 63.

In another embodiment, an altered targeting domain is derived from a GDF11. In another embodiment, an altered targeting domain is derived from a GDF11 of SEQ ID NO: 64. In an aspect of this embodiment, an altered targeting domain is derived from a GDF11 comprising amino acids 313-407 of SEQ ID NO: 64.

In another embodiment, an altered targeting domain is derived from a GDF15. In another embodiment, an altered targeting domain is derived from a GDF15 of SEQ ID NO: 65. In an aspect of this embodiment, an altered targeting domain is derived from a GDF15 comprising amino acids 211-308 of SEQ ID NO: 65.

Another example of an altered targeting domain disclosed in the present specification is, e.g., an activin A, an activin B, an activin C, an activin E or an inhibin A.

In another embodiment, an altered targeting domain is derived from an Activin A. In another embodiment, an altered targeting domain is derived from an Activin A of SEQ ID NO: 66. In an aspect of this embodiment, an altered targeting domain is derived from an Activin A comprising amino acids 321-426 of SEQ ID NO: 66.

In another embodiment, an altered targeting domain is derived from an Activin B. In another embodiment, an altered targeting domain is derived from an Activin B of SEQ ID NO: 67. In an aspect of this embodiment, an altered targeting domain is derived from an Activin B comprising amino acids 303-406 of SEQ ID NO: 67.

In another embodiment, an altered targeting domain is derived from an Activin C. In another embodiment, an altered targeting domain is derived from an Activin C of SEQ ID NO: 68. In an aspect of this embodiment, an altered targeting domain is derived from an Activin C comprising amino acids 247-352 or amino acids 237-352 of SEQ ID NO: 68.

In another embodiment, an altered targeting domain is derived from an Activin E. In another embodiment, an altered targeting domain is derived from an Activin E of SEQ ID NO: 69. In an aspect of this embodiment, an altered targeting domain is derived from an Activin E comprising amino acids 247-350 of SEQ ID NO: 69.

In another embodiment, an altered targeting domain is derived from an Inhibin A. In another embodiment, an altered targeting domain is derived from an Inhibin A of SEQ ID NO: 70. In an aspect of this embodiment, an altered targeting domain is derived from an Inhibin A comprising amino acids 262-366 or amino acids 233-366 of SEQ ID NO: 70.

An altered targeting domain disclosed in the present specification replaces the binding activity of the Clostridial toxin targeting domain found in naturally occurring Clostridial toxins. As used herein, the term “Clostridial toxin targeting domain” is synonymous with “Clostridial toxin HCC targeting region” or “Clostridial toxin HCC region” and means any naturally occurring Clostridial toxin polypeptide that can execute the cell binding step of the intoxication process, including, e.g., the binding of the Clostridial toxin to a Clostridial toxin-specific receptor located on the plasma membrane surface of a target cell. It is envisioned that replacement of the binding activity can be achieved by, e.g., replacing the entire Clostridial toxin HCC targeting domain with an altered targeting domain; replacing a portion of a Clostridial toxin HCC targeting domain with an altered targeting domain, with the proviso that the portion of a Clostridial toxin HCC targeting domain remaining cannot selectively bind to its Clostridial toxin receptor; and operably-linking an altered targeting domain to a Clostridial toxin comprising a Clostridial toxin HCC targeting domain, with the proviso that the a Clostridial toxin HCC targeting domain is altered so that it cannot selectively bind to its Clostridial toxin receptor.

The three-dimensional crystal structures of BoNT/A, BoNT/B and the HC domain of TeNT indicate that the three functional domains of Clostridial neurotoxins are structurally distinct. The HEXXH consensus motif of the light chain forms the tetrahedral zinc binding pocket of the catalytic site located in a deep cleft on the protein surface that is accessible by a channel. The structure of the HN and HC domains consists primarily of β-sheet topologies that are linked by a single α-helix. The cylindrical-shaped HN domain comprises two long amphipathic α-helices that resemble the coiled-coil motif found in some viral proteins. The HN domain also forms a long unstructured loop called the ‘translocation belt,’ which wraps around a large negatively charged cleft of the light chain that blocks access of the zinc atom to the catalytic-binding pocket of active site. The HC domain comprises two distinct structural features of roughly equal size that indicate function. The first, designated the HCN domain, is located in the amino half of the HC domain. The HCN domain forms a β-barrel, jelly-roll fold. The HCC domain is the second domain that comprises the HC domain. This carboxyl-terminal domain comprises a modified β-trefoil domain which forms three distinct carbohydrate binding regions that resembles the carbohydrate binding moiety found in many sugar-binding proteins, such as, e.g., serum amyloid P, sialidase, cryia, insecticidal ∂-endotoxin and lectins. Biochemical studies indicate that the β-trefoil domain structure of the HCC domain appears to mediate the binding to specific carbohydrate containing components of the Clostridial toxin receptor on the cell surface, see, e.g., Krzysztof Ginalski et al., Structure-based Sequence Alignment for the Beta-Trefoil Subdomain of the Clostridial Neurotoxin Family Provides Residue Level Information About the Putative Ganglioside Binding Site, 482(1-2) FEBS Lett. 119-124 (2000). The HC domain tilts away from the HN domain exposing the surface loops and making them accessible for binding. No contacts occur between the light chain and the HC domain.

Proteins containing the structural β-trefoil domain represents a diverse group of proteins, see, e.g., C. A. Orengo et al., Protein Superfamilies and Domain Superfolds, 372 Nature 631-634 (1994). The β-trefoil domain comprises a six-stranded β-barrel closed off at one end by three β-hairpin structures that exhibits a characteristic pseudo-threefold axis symmetry. The monomeric structural unit of this three-fold symmetry is referred to as the β-trefoil fold that contains four β-sheets organized as a pair of antiparallel β-sheets. Dividing each of these β-trefoil folds is a β-hairpin turn. Therefore, in a linear fashion, a β-trefoil domain comprises four β-sheets of the first β-trefoil fold, a β-hairpin turn, four β-sheets of the second β-trefoil fold, a second β-hairpin turn four β-sheets of the third β-trefoil fold. Because the first hairpin turn is located between the fourth and fifth β-sheets of the β-trefoil domain, it is designated the β4/β5 β-hairpin turn. Likewise, since the second hairpin turn is located between the eight and ninth β-sheets of the β-trefoil domain, it is designated the β8/β9 β-hairpin turn.

As is typical for proteins containing a β-trefoil fold, the overall amino acid sequence identity of the HCC domain between Clostridial toxins is low. However, key residues essential for binding activity have been identified by structural analysis and mutagenesis experiments, see, e.g., Krzysztof Ginalski et al., Structure-based Sequence Alignment for the Beta-Trefoil Subdomain of the Clostridial Neurotoxin Family Provides Residue Level Information About the Putative Ganglioside Binding Site, 482(1-2) FEBS Lett. 119-124 (2000); and Andreas Rummel et al., The HCC-Domain of Botulinum Neurotoxins A and B Exhibits a Singular Ganglioside Binding Site Displaying Serotype Specific Carbohydrate Interaction, 51(3) Mol. Microbiol. 631-643 (2004). Additionally, research has elucidated that β4/β5 and β8/β9 β-hairpin turns are important in conferring the proper pseudo-threefold axis symmetry observed in the β-trefoil domain and that these turns are important for β-trefoil domain stability, see, e.g., Stephen R. Brych et al., Structure and Stability Effects of Mutations Designed to Increase the Primary Sequence Symmetry Within the Core Region of a β-trefoil, 10 Protein Sci. 2587-2599 (2001); Jaewon Kim et al., Alternative Type I and I′ Turn Conformations in the β8/β9β-hairpin of Human Acidic Fibroblast Growth Factor, 11 Protein Sci. 459-466 (2002); Jaewon Kim et al., Sequence swapping Does Not Result in Conformation Swapping for the β4/β5 and β8/β9 β-hairpin Turns in Human Acidic Fibroblast Growth Factor, 14 Protein Sci. 351-359 (2005). The amino acid sequences comprising the β-trefoil domains found in various Clostridial toxins are shown in Table 2.

TABLE 2

β-trefoil Domains of Clostridial Toxins

Amino Acid Sequence Region of Carbohydrate Binding Moieties

β4/β5

β8/β9

Protein

SEQ ID NO:

α-fold

β-hairpin turn

β-fold

β-hairpin turn

γ-fold

BoNT/A

1

1111-1162

1163-1178

1179-1223

1224-1236

1237-1296

BoNT/B

2

1098-1147

1148-1165

1166-1210

1211-1222

1223-1291

BoNT/C1

3

1112-1150

1151-1166

1167-1218

1219-1229

1230-1291

BoNT/D

4

1099-1137

1138-1153

1154-1207

1208-1218

1219-1276

BoNT/E

5

1086-1129

1130-1146

1147-1190

1191-1198

1199-1252

BoNT/F

6

1106-1152

1153-1171

1172-1213

1214-1221

1222-1274

BoNT/G

7

1106-1153

1154-1172

1173-1218

1219-1230

1231-1297

TeNT

8

1128-1177

1178-1194

1195-1240

1241-1254

1255-1315

Thus, in an embodiment, a Clostridial toxin targeting domain comprising an HCC region can be replaced with an enhance binding domain disclosed in the present specification. In aspects of this embodiment, a BoNT/A HCC region can be replaced with an altered targeting domain, a BoNT/B HCC region can be replaced with an altered targeting domain, a BoNT/C1 HCC region can be replaced with an altered targeting domain, a BoNT/D HCC region can be replaced with an altered targeting domain, a BoNT/E HCC region can be replaced with an altered targeting domain, a BoNT/F HCC region can be replaced with an altered targeting domain, a BoNT/G HCC region can be replaced with an altered targeting domain and a TeNT HCC region can be replaced with an altered targeting domain.

In aspects of this embodiment, a BoNT/A HCC region can be replaced with an altered targeting domain, a BoNT/B HCC region can be replaced with an altered targeting domain, a BoNT/C1 HCC region can be replaced with an altered targeting domain, a BoNT/D HCC region can be replaced with an altered targeting domain, a BoNT/E HCC region can be replaced with an altered targeting domain, a BoNT/F HCC region can be replaced with an altered targeting domain, a BoNT/G HCC region can be replaced with an altered targeting domain and a TeNT HCC region can be replaced with an altered targeting domain. In other aspects of this embodiment, a BoNT/A HCC region comprising amino acids 1092-1296 of SEQ ID NO: 1 can be replaced with an altered targeting domain, a BoNT/B HCC region comprising amino acids 1079-1291 of SEQ ID NO: 2 can be replaced with an altered targeting domain, a BoNT/C1 HCC region comprising amino acids 1093-1291 of SEQ ID NO: 3 can be replaced with an altered targeting domain, a BoNT/D HCC region comprising amino acids 1080-1276 of SEQ ID NO: 4 can be replaced with an altered targeting domain, a BoNT/E HCC region comprising amino acids 1067-1252 of SEQ ID NO: 5 can be replaced with an altered targeting domain, a BoNT/F HCC region comprising amino acids 1087-1274 of SEQ ID NO: 6 can be replaced with an altered targeting domain, a BoNT/G HCC region comprising amino acids 1087-1297 of SEQ ID NO: 7 can be replaced with an altered targeting domain and a TeNT HCC region comprising amino acids 1109-1315 of SEQ ID NO: 8 can be replaced with an altered targeting domain.

In another embodiment, an enhance binding domain disclosed in the present specification is operably-linked to a Clostridial toxin comprising a Clostridial toxin targeting domain altered so that it cannot selectively bind to its Clostridial toxin receptor. As used herein, the term “altered,” when referring to a Clostridial toxin targeting domain, means a naturally occurring Clostridial toxin targeting domain modified to eliminate or reduce the binding activity of the Clostridial toxin targeting domain so that the domain can no longer selectively bind to a Clostridial toxin receptor. By definition, an altered Clostridial toxin targeting domain has at least one amino acid change from the corresponding region of the disclosed reference sequences (see Table 1) and can be described in percent identity to the corresponding region of that reference sequence. As non-limiting examples, a modified BoNT/A HCC region comprising amino acids 1111-1296 of SEQ ID NO: 1 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1111-1296 of SEQ ID NO: 1; a modified BoNT/B HCC region comprising amino acids 1098-1291 of SEQ ID NO: 2 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1098-1291 of SEQ ID NO: 2; a modified BoNT/C1 HCC region comprising amino acids 1112-1291 of SEQ ID NO: 3 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1112-1291 of SEQ ID NO: 3; a modified BoNT/D HCC region comprising amino acids 1099-1276 of SEQ ID NO: 4 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1099-1276 of SEQ ID NO: 4; a modified BoNT/E HCC region comprising amino acids 1086-1252 of SEQ ID NO: 5 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1086-1252 of SEQ ID NO: 5; a modified BoNT/F HCC region comprising amino acids 1106-1274 of SEQ ID NO: 6 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1106-1274 of SEQ ID NO: 6; a modified BoNT/G HCC region comprising amino acids 1106-1297 of SEQ ID NO: 7 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1106-1297 of SEQ ID NO: 7; and a modified TeNT HCC region comprising amino acids 1128-1315 of SEQ ID NO: 8 will have at least one amino acid difference, such as, e.g., an amino acid substitution, deletion or addition, as compared to the amino acid region 1128-1315 of SEQ ID NO: 8.

In aspects of this embodiment, an altered Clostridial toxin HCC targeting region comprises a polypeptide having, e.g., at least 70% amino acid identity with its reference sequence, at least 75% amino acid identity with its reference sequence, at least 80% amino acid identity with its reference sequence, at least 85% amino acid identity with its reference sequence, at least 90% amino acid identity with its reference sequence or at least 95% amino acid identity with its reference sequence. In yet other aspects of this embodiment, an altered Clostridial toxin HCC targeting region comprises a polypeptide having, e.g., at most 70% amino acid identity with its reference sequence, at most 75% amino acid identity with its reference sequence, at most 80% amino acid identity with its reference sequence, at most 85% amino acid identity with its reference sequence, at most 90% amino acid identity with its reference sequence or at most 95% amino acid identity with its reference sequence.

An asterisks (*) indicates the peptide bond that is cleaved by a Clostridial toxin protease.

In is envisioned that any and all protease cleavage sites can be used to convert the single-chain polypeptide form of a Clostridial toxin into the di-chain form, including, without limitation, endogenous di-chain loop protease cleavage sites and exogenous protease cleavage sites. The location and kind of protease cleavage site may be critical because certain targeting domains require a free amino-terminal or carboxyl-terminal amino acid. For example, when a targeting domain is placed between two other domains, e.g., see FIG. 5, a criteria for selection of a protease cleavage site could be whether the protease that cleaves its site leaves a flush cut, exposing the free amino-terminal or carboxyl-terminal of the altered targeting domain necessary for selective binding of the targeting domain to its receptor. The selection and placement of a protease cleavage site is well known in the art.

As mentioned above, Clostridial toxins are translated as a single-chain polypeptide of approximately 150 kDa that is subsequently cleaved by proteolytic scission within a disulfide loop by a naturally-occurring protease. This posttranslational processing yields a di-chain molecule comprising an approximately 50 kDa light chain (LC) and an approximately 100 kDa heavy chain (HC) held together by a single disulphide bond and noncovalent interactions. While the identity of the protease is currently unknown, the di-chain loop protease cleavage site for many Clostridial toxins has been proposed. In BoNTs, cleavage at K448-A449 converts the single polypeptide form of BoNT/A into the di-chain form; cleavage at K441-A442 converts the single polypeptide form of BoNT/B into the di-chain form; cleavage at K449-T450 converts the single polypeptide form of BoNT/C1 into the di-chain form; cleavage at R445-D446 converts the single polypeptide form of BoNT/D into the di-chain form; cleavage at R422-K423 converts the single polypeptide form of BoNT/E into the di-chain form; cleavage at K439-A440 converts the single polypeptide form of BoNT/F into the di-chain form; and cleavage at K446-S447 converts the single polypeptide form of BoNT/G into the di-chain form. Proteolytic cleavage of the single polypeptide form of TeNT at A457-S458 results in the di-chain form. Such a di-chain loop protease cleavage site is operably-linked in-frame to a modified Clostridial toxin as a fusion protein.

However, it should also be noted that additional cleavage sites within the di-chain loop also appear to be cleaved resulting in the generation of a small peptide fragment being lost. As a non-limiting example, BoNT/A single-chain polypeptide cleave ultimately results in the loss of a ten amino acid fragment within the di-chain loop. Thus, in BoNTs, cleavage at S441-L442 converts the single polypeptide form of BoNT/A into the di-chain form; cleavage at G444-1445 converts the single polypeptide form of BoNT/B into the di-chain form; cleavage at S445-L446 converts the single polypeptide form of BoNT/C1 into the di-chain form; cleavage at K442-N443 converts the single polypeptide form of BoNT/D into the di-chain form; cleavage at K419-G420 converts the single polypeptide form of BoNT/E into the di-chain form; cleavage at K423-S424 converts the single polypeptide form of BoNT/E into the di-chain form; cleavage at K436-G437 converts the single polypeptide form of BoNT/F into the di-chain form; cleavage at T444-G445 converts the single polypeptide form of BoNT/G into the di-chain form; and cleavage at E448-Q449 converts the single polypeptide form of BoNT/G into the di-chain form.

Thus, in an embodiment, a protease cleavage site comprising an endogenous Clostridial toxin di-chain loop protease cleavage site is used to convert the single-chain toxin into the di-chain form. In aspects of this embodiment, conversion into the di-chain form by proteolytic cleavage occurs from a site comprising, e.g., a BoNT/A di-chain loop protease cleavage site, a BoNT/B di-chain loop protease cleavage site, a BoNT/C1 di-chain loop protease cleavage site, a BoNT/D di-chain loop protease cleavage site, a BoNT/E di-chain loop protease cleavage site, a BoNT/F di-chain loop protease cleavage site, a BoNT/G di-chain loop protease cleavage site or a TeNT di-chain loop protease cleavage site.

It is also envisioned that an exogenous protease cleavage site can be used to convert the single-chain polypeptide form of a modified Clostridial toxin disclosed in the present specification into the di-chain form. As used herein, the term “exogenous protease cleavage site” is synonymous with a “non-naturally occurring protease cleavage site” and means a protease cleavage site that is not normally present in a di-chain loop region from a naturally occurring Clostridial toxin. Non-limiting examples of exogenous protease cleavage sites include, e.g., an enterokinase cleavage site (Table 4); a Thrombin cleavage site (Table 4); a Factor Xa cleavage site (Table 4); a human rhinovirus 3C protease cleavage site (Table 4); a tobacco etch virus (TEV) protease cleavage site (Table 4); a dipeptidyl aminopeptidase cleavage site; a small ubiquitin-like modifier (SUMO)/ubiquitin-like protein-1 (ULP-1) protease cleavage site, such as, e.g., MADSEVNQEAKPEVKPEVKPETHINLKVSDGSSEIFFKIKKTTPLRRLMEAFAKRQGK EMDSLRFLYDGIRIQADQTPEDLDMEDNDIIEAHREQIGG (SEQ ID. NO: 57); and a Clostridial toxin substrate cleavage site.

TABLE 4

Exogenous Protease Cleavage Sites

Protease Cleavage

Non-limiting

SEQ ID

Site

Consensus Sequence

Examples

NO:

Bovine enterokinase

DDDDK*

DDDDK*

71

Tobacco Etch Virus

E P5 P4YP2Q*(G/S),

ENLYFQ*G

72

(TEV)

where P2, P4 and P5 can be any amino acid

ENLYFQ*S

73

ENIYTQ*G

74

ENIYTQ*S

75

ENIYLQ*G

76

ENIYLQ*S

77

ENVYFQ*G

78

ENVYSQ*S

79

ENVYSQ*G

80

ENVYSQ*S

81

Human Rhinovirus 3C

P5P4LFQ*GP

EALFQ*GP

82

where P4 is G, A, V, L, I, M, S or T and P5 can any

EVLFQ*GP

83

amino acid, with D or E preferred.

ELLFQ*GP

84

DALFQ*GP

85

DVLFQ*GP

86

DLLFQ*GP

87

SUMO/ULP-1

Tertiary structure

polypeptide-G*

88

Thrombin

P3P2(R/K)*P1′,

GVR*G

89

where P3 is any amino acid and P2 or P1′ is G with

SAR*G

90

the other position being any amino acid

SLR*G

91

DGR*I

92

QGK*I

93

Thrombin

P4P3P(R/K)*P1′ P2′

LVPR*GS

94

where P1′ and P2′ can be any amino acid except for

LVPK*GS

95

acidic amino acids like D or E; and P3 and P4 are

FIPR*TF

96

hydrophobic amino acids like F, L, I, Y, W, V, M, P,

VLPR*SF

97

C or A

IVPR*SF

98

IVPR*GY

99

VVPR*GV

100

VLPR*LI

101

VMPR*SL

102

MFPR*SL

103

Coagulation Factor Xa

I(E/D)GR*

IDGR*

104

IEGR*

105

An asterisks (*) indicates the peptide bond that is cleaved by the indicated protease.

As mentioned above, a Clostridial toxin is converted from a single polypeptide form into a di-chain molecule by proteolytic cleavage. While the naturally-occurring protease is currently not known, cleavage occurs within the di-chain loop region between the two cysteine residues that form the disulfide bridge (see Table 3). Replacement of an endogenous protease cleavage site with an exogenous protease cleavage site will enable cleavage of a modified Clostridial toxin disclosed in the present specification when expressed in an organism that does not produce the naturally-occurring protease used to cleave the di-chain loop region of a toxin. Similarly, an addition of an exogenous protease cleavage site in the di-chain loop region will also enable cleavage of a modified Clostridial toxin disclosed in the present specification when expressed in an organism that does not produce the naturally-occurring protease used to cleave the di-chain loop region of a toxin.

It is envisioned that an exogenous protease cleavage site of any and all lengths can be useful in aspects of the present invention with the proviso that the exogenous protease cleavage site is capable of being cleaved by its respective protease. Thus, in aspects of this embodiment, an exogenous protease cleavage site can be, e.g., at least 6 amino acids in length, at least 7 amino acids in length, at least 8 amino acids in length, at least 9 amino acids in length, at least 10 amino acids in length, at least 15 amino acids in length, at least 20 amino acids in length, at least 25 amino acids in length, at least 30 amino acids in length, at least 40 amino acids in length, at least 50 amino acids in length or at least 60 amino acids in length. In other aspects of this embodiment, an exogenous protease cleavage site can be, e.g., at most 6 amino acids in length, at most 7 amino acids in length, at most 8 amino acids in length, at most 9 amino acids in length, at most 10 amino acids in length, at most 15 amino acids in length, at most 20 amino acids in length, at most 25 amino acids in length, at most 30 amino acids in length, at most 40 amino acids in length, at most 50 amino acids in length or at most 60 amino acids in length.

In aspects of this embodiment, a di-chain loop region can be modified to substitute a naturally-occurring protease cleavage site for an exogenous protease cleavage site. In this type of modification, the naturally-occurring protease cleavage site is made inoperable and thus can not be cleaved by its protease. Only the exogenous protease cleavage site can be cleaved by its corresponding exogenous protease. In this type of modification, the exogenous protease site is operably-linked in-frame to a modified Clostridial toxin as a fusion protein and the site can be cleaved by its respective exogenous protease. As a non-limiting example, a single-chain modified BoNT/A comprising an exogenous protease cleavage site in the di-chain loop region can be cleaved by its respective exogenous protease to produce the di-chain form of the toxin.

In other aspects of this embodiment, a di-chain loop region can be modified to include an exogenous protease cleavage site in addition to the naturally-occurring protease cleavage site. In this type of modification, both cleavage sites are operably-linked in-frame to a modified Clostridial toxin as a fusion protein and both sites can be cleaved by their respective proteases. As a non-limiting example, a single-chain modified BoNT/A that comprises a di-chain loop containing both the naturally-occurring BoNT/A di-chain loop protease cleavage site and an exogenous protease cleavage site can be cleaved by either the naturally occurring di-chain loop protease or by the appropriate exogenous protease to produce the di-chain form of the toxin.

A naturally-occurring protease cleavage site can be made inoperable by altering at least the two amino acids flanking the peptide bond cleaved by the naturally-occurring di-chain loop protease. More extensive alterations can be made, with the proviso that the two cysteine residues of the di-chain loop region remain intact and can still form the disulfide bridge. Non-limiting examples of an amino acid alteration include deletion of an amino acid or replacement of the original amino acid with a different amino acid. Thus, in one embodiment, a naturally-occurring protease cleavage site is made inoperable by altering the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease. In other aspects of this embodiment, a naturally-occurring protease cleavage site is made inoperable by altering, e.g., at least three amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least four amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least five amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least six amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least seven amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least eight amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least nine amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least ten amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at least 15 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; or at least 20 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease.

In still other aspects of this embodiment, a naturally-occurring di-chain protease cleavage site is made inoperable by altering, e.g., at most three amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most four amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most five amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most six amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most seven amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most eight amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most nine amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most ten amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; at most 15 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease; or at most 20 amino acids including the two amino acids flanking the peptide bond cleaved by a naturally-occurring protease.

In an embodiment, an exogenous protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In aspects of this embodiment, a modified Clostridial toxin comprises an exogenous protease cleavage site comprises, e.g., a bovine enterokinase protease cleavage site, a Tobacco Etch Virus protease cleavage site, a Human Rhinovirus 3C protease cleavage site, a SUMO/ULP-1 protease cleavage site, a Thrombin protease cleavage site or a Factor Xa protease cleavage site. In other aspects of this embodiment, an exogenous protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

In an aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a bovine enterokinase cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a bovine enterokinase protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 71. Is still other aspects of this embodiment, a bovine enterokinase protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

In another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Tobacco Etch Virus protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Tobacco Etch Virus protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80 or SEQ ID NO: 81. Is still other aspects of this embodiment, a Tobacco Etch Virus protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

In still another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Human Rhinovirus 3C protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Human Rhinovirus 3C protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 86 or SEQ ID NO: 87. Is still other aspects of this embodiment, a Human Rhinovirus 3C protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

In yet another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a SUMO/ULP-1 protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a SUMO/ULP-1 protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 88. Is still other aspects of this embodiment, a SUMO/ULP-1 protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

In a further aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Thrombin protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Thrombin protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99, SEQ ID NO: 100, SEQ ID NO: 101, SEQ ID NO: 102 or SEQ ID NO: 103. Is still other aspects of this embodiment, a Thrombin protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

In another aspect of this embodiment, an exogenous protease cleavage site can be, e.g., a Coagulation Factor Xa protease cleavage site is located within the di-chain loop of a modified Clostridial toxin. In other aspects of the embodiment, an exogenous protease cleavage site can be, e.g., a Coagulation Factor Xa protease cleavage site located within the di-chain loop of a modified Clostridial toxin comprises SEQ ID NO: 104 or SEQ ID NO: 105. Is still other aspects of this embodiment, a Coagulation Factor Xa protease cleavage site is located within the di-chain loop of, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

In another embodiment, an exogenous protease site comprises a Clostridial toxin substrate cleavage site. As used herein, the term “Clostridial toxin substrate cleavage site” means a scissile bond together with adjacent or non-adjacent recognition elements, or both, sufficient for detectable proteolysis at the scissile bond by a Clostridial toxin under conditions suitable for Clostridial toxin protease activity. By definition, a Clostridial toxin substrate cleavage site is susceptible to cleavage by at least one Clostridial toxin under conditions suitable for Clostridial toxin protease activity. Non-limiting examples of Clostridial toxin substrate cleavage site are disclosed in, e.g., Lance E. Steward et al., Self-Activating Clostridial Toxins, U.S. Patent Application 60/718,616 (Sep. 19, 2005).

It is understood that a modified Clostridial toxin disclosed in the present specification can optionally include one or more additional components. As a non-limiting example of an optional component, a modified Clostridial toxin can further comprise a flexible region comprising a flexible spacer. Non-limiting examples of a flexible spacer include, e.g., a G-spacer GGGGS (SEQ ID NO: 106) or an A-spacer EAAAK (SEQ ID NO: 107). A flexible region comprising flexible spacers can be used to adjust the length of a polypeptide region in order to optimize a characteristic, attribute or property of a polypeptide. Such a flexible region is operably-linked in-frame to the modified Clostridial toxin as a fusion protein. As a non-limiting example, a polypeptide region comprising one or more flexible spacers in tandem can be use to better expose a protease cleavage site thereby facilitating cleavage of that site by a protease. As another non-limiting example, a polypeptide region comprising one or more flexible spacers in tandem can be use to better present an altered targeting domain, thereby facilitating the binding of that altered targeting domain to its receptor.

Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise a flexible region comprising a flexible spacer. In another embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise flexible region comprising a plurality of flexible spacers in tandem. In aspects of this embodiment, a flexible region can comprise in tandem, e.g., at least 1 G-spacer, at least 2 G-spacers, at least 3 G-spacers, at least 4 G-spacers or at least 5 G-spacers. In other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at most 1 G-spacer, at most 2 G-spacers, at most 3 G-spacers, at most 4 G-spacers or at most 5 G-spacers. In still other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at least 1 A-spacer, at least 2 A-spacers, at least 3 A-spacers, at least 4 A-spacers or at least 5 A-spacers. In still other aspects of this embodiment, a flexible region can comprise in tandem, e.g., at most 1 A-spacer, at most 2 A-spacers, at most 3 A-spacers, at most 4 A-spacers or at most 5 A-spacers. In another aspect of this embodiment, a modified Clostridial toxin can comprise a flexible region comprising one or more copies of the same flexible spacers, one or more copies of different flexible-spacer regions, or any combination thereof.

In aspects of this embodiment, a modified Clostridial toxin comprising a flexible spacer can be, e.g., a modified BoNT/A, a modified BoNT/B, a modified BoNT/C1, a modified BoNT/D, a modified BoNT/E, a modified BoNT/F, a modified BoNT/G or a modified TeNT.

It is envisioned that a modified Clostridial toxin disclosed in the present specification can comprise a flexible spacer in any and all locations with the proviso that modified Clostridial toxin is capable of performing the intoxication process. In aspects of this embodiment, a flexible spacer is positioned between, e.g., an enzymatic domain and a translocation domain, an enzymatic domain and an altered targeting domain, an enzymatic domain and a protease cleavage site. In other aspects of this embodiment, a G-spacer is positioned between, e.g., an enzymatic domain and a translocation domain, an enzymatic domain and an altered targeting domain, an enzymatic domain and a protease cleavage site. In other aspects of this embodiment, a A-spacer is positioned between, e.g., an enzymatic domain and a translocation domain, an enzymatic domain and an altered targeting domain, an enzymatic domain and a protease cleavage site.

In other aspects of this embodiment, a flexible spacer is positioned between, e.g., an altered targeting domain and a translocation domain, an altered targeting domain and an enzymatic domain, an altered targeting domain and a protease cleavage site. In other aspects of this embodiment, a G-spacer is positioned between, e.g., an altered targeting domain and a translocation domain, an altered targeting domain and an enzymatic domain, an altered targeting domain and a protease cleavage site. In other aspects of this embodiment, a A-spacer is positioned between, e.g., an altered targeting domain and a translocation domain, an altered targeting domain and an enzymatic domain, an altered targeting domain and a protease cleavage site.

In yet other aspects of this embodiment, a flexible spacer is positioned between, e.g., a translocation domain and an enzymatic domain, an translocation domain and an altered targeting domain, an translocation domain and a protease cleavage site. In other aspects of this embodiment, a G-spacer is positioned between, e.g., a translocation domain and an enzymatic domain, an translocation domain and an altered targeting domain, an translocation domain and a protease cleavage site. In other aspects of this embodiment, a A-spacer is positioned between, e.g., a translocation domain and an enzymatic domain, an translocation domain and an altered targeting domain, a translocation domain and a protease cleavage site.

Thus, in an embodiment, a modified Clostridial toxin disclosed in the present specification can further comprise an epitope-binding region. In another embodiment, a modified Clostridial toxin disclosed in the present specification can further comprises a plurality of epitope-binding regions. In aspects of this embodiment, a modified Clostridial toxin can comprise, e.g., at least 1 epitope-binding region, at least 2 epitope-binding regions, at least 3 epitope-binding regions, at least 4 epitope-binding regions or at least 5 epitope-binding regions. In other aspects of this embodiment, a modified Clostridial toxin can comprise, e.g., at most 1 epitope-binding region, at most 2 epitope-binding regions, at most 3 epitope-binding regions, at most 4 epitope-binding regions or at most 5 epitope-binding regions. In another aspect of this embodiment, a modified Clostridial toxin can comprise one or more copies of the same epitope-binding region, one or more copies of different epitope-binding regions, or any combination thereof.

The location of an epitope-binding region can be in various positions, including, without limitation, at the amino terminus of a modified Clostridial toxin, within a modified Clostridial toxin, or at the carboxyl terminus of a modified Clostridial toxin. Thus, in an embodiment, an epitope-binding region is located at the amino-terminus of a modified Clostridial toxin. In such a location, a start methionine should be placed in front of the epitope-binding region. In addition, it is known in the art that when adding a polypeptide that is operationally-linked to the amino terminus of another polypeptide comprising the start methionine that the original methionine residue can be deleted. This is due to the fact that the added polypeptide will contain a new start methionine and that the original start methionine may reduce optimal expression of the fusion protein. In aspects of this embodiment, an epitope-binding region located at the amino-terminus of a modified Clostridial toxin disclosed in the present specification can be, e.g., a FLAG, Express™ epitope-binding region, a human Influenza virus hemagluttinin (HA) epitope-binding region, a human p62c-Myc protein (c-MYC) epitope-binding region, a Vesicular Stomatitis Virus Glycoprotein (VSV-G) epitope-binding region, a Substance P epitope-binding region, a glycoprotein-D precursor of Herpes simplex virus (HSV) epitope-binding region, a V5 epitope-binding region, a AU1 epitope-binding region, a AU5 epitope-binding region, a polyhistidine epitope-binding region, a streptavidin binding peptide epitope-binding region, a biotin epitope-binding region, a biotinylation epitope-binding region, a glutathione binding domain of glutathione-S-transferase, a calmodulin binding domain of the calmodulin binding protein or a maltose binding domain of the maltose binding protein.

In another embodiment, an epitope-binding region is located at the carboxyl-terminus of a modified Clostridial toxin. In aspects of this embodiment, an epitope-binding region located at the carboxyl-terminus of a modified Clostridial toxin disclosed in the present specification can be, e.g., a FLAG, Express™ epitope-binding region, a human Influenza virus hemagluttinin (HA) epitope-binding region, a human p62c-Myc protein (c-MYC) epitope-binding region, a Vesicular Stomatitis Virus Glycoprotein (VSV-G) epitope-binding region, a Substance P epitope-binding region, a glycoprotein-D precursor of Herpes simplex virus (HSV) epitope-binding region, a V5 epitope-binding region, a AU1 epitope-binding region, a AU5 epitope-binding region, a polyhistidine epitope-binding region, a streptavidin binding peptide epitope-binding region, a biotin epitope-binding region, a biotinylation epitope-binding region, a glutathione binding domain of glutathione-S-transferase, a calmodulin binding domain of the calmodulin binding protein or a maltose binding domain of the maltose binding protein.

It is envisioned that a modified Clostridial toxin disclosed in the present specification can comprise an altered targeting domain in any and all locations with the proviso that modified Clostridial toxin is capable of performing the intoxication process. Non-limiting examples include, locating an enhance targeting domain at the amino terminus of a modified Clostridial toxin (see FIG. 4); locating an enhance targeting domain between a Clostridial toxin enzymatic domain and a Clostridial toxin translocation domain of a modified Clostridial toxin (see FIG. 5); and locating an enhance targeting domain at the carboxyl terminus of a modified Clostridial toxin (see FIG. 6). The enzymatic domain of naturally-occurring Clostridial toxins contains the native start methionine. Thus, in domain organizations where the enzymatic domain is not in the amino-terminal location an amino acid sequence comprising the start methionine should be placed in front of the amino-terminal domain. Likewise, where the altered targeting domain is in the amino-terminal position, an amino acid sequence comprising a start methionine and a protease cleavage site may be operably-linked in situations in which the altered targeting domain requires a free amino terminus, see, e.g., Shengwen Li et al., Degradable Clostridial Toxins, International Patent Application Publication WO 2006/026780 (Mar. 9, 2006). In addition, it is known in the art that when adding a polypeptide that is operably-linked to the amino terminus of another polypeptide comprising the start methionine that the original methionine residue can be deleted.

Thus, in an embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain and an altered targeting domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, a protease cleavage site, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain and an altered targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an endogenous protease cleavage site, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain and an altered targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain and an altered targeting domain.

In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an altered targeting domain, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, a protease cleavage site, an altered targeting domain, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an endogenous protease cleavage site, an altered targeting domain, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, an altered targeting domain, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain.

In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain and a Clostridial toxin enzymatic domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain, a protease cleavage site and a Clostridial toxin enzymatic domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain, an endogenous protease cleavage site and a Clostridial toxin enzymatic domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain, an exogenous protease cleavage site and a Clostridial toxin enzymatic domain.

In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin enzymatic domain, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin enzymatic domain, a protease cleavage site, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin enzymatic domain, an endogenous protease cleavage site, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising an altered targeting domain, a Clostridial toxin enzymatic domain, an exogenous protease cleavage site, a Clostridial toxin translocation domain and a Clostridial toxin translocation facilitating domain.

In another embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain, a Clostridial toxin enzymatic domain and an altered targeting domain. In an aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain, a protease cleavage site, a Clostridial toxin enzymatic domain and an altered targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain, an endogenous protease cleavage site, a Clostridial toxin enzymatic domain and an altered targeting domain. In another aspect of this embodiment, a modified Clostridial toxin can comprise an amino to carboxyl single polypeptide linear order comprising a Clostridial toxin translocation domain, a Clostridial toxin translocation facilitating domain, an exogenous protease cleavage site, a Clostridial toxin enzymatic domain and an altered targeting domain.

Aspects of the present invention provide, in part modified Clostridial toxins. Non-limiting examples of Clostridial toxin modifications disclosed in the present specification include, e.g., addition of an altered targeting domain, addition of a protease cleavage site, rearrangement of the enzymatic, translocation and binding domains and addition of a spacer region. It is understood that all such modifications do not substantially affect the ability of a modified Clostridial toxin to intoxicate a cell. As used herein, the term “do not substantially affect” means a modified Clostridial toxin can still execute the overall cellular mechanism whereby a Clostridial toxin enters a neuron and inhibits neurotransmitter release and encompasses the binding of a Clostridial toxin to a low or high affinity receptor complex, the internalization of the toxin/receptor complex, the translocation of the Clostridial toxin light chain into the cytoplasm and the enzymatic modification of a Clostridial toxin substrate. In aspects of this embodiment, the modified Clostridial toxin is, e.g., at least 10% as toxic as a naturally-occurring Clostridial toxin, at least 20% as toxic as a naturally-occurring Clostridial toxin, at least 30% as toxic as a naturally-occurring Clostridial toxin, at least 40% as toxic as a naturally-occurring Clostridial toxin, at least 50% as toxic as a naturally-occurring Clostridial toxin, at least 60% as toxic as a naturally-occurring Clostridial toxin, at least 70% as toxic as a naturally-occurring Clostridial toxin, at least 80% as toxic as a naturally-occurring Clostridial toxin, at least 90% as toxic as a naturally-occurring Clostridial toxin or at least 95% as toxic as a naturally-occurring Clostridial toxin. In aspects of this embodiment, the modified Clostridial toxin is, e.g., at most 10% as toxic as a naturally-occurring Clostridial toxin, at most 20% as toxic as a naturally-occurring Clostridial toxin, at most 30% as toxic as a naturally-occurring Clostridial toxin, at most 40% as toxic as a naturally-occurring Clostridial toxin, at most 50% as toxic as a naturally-occurring Clostridial toxin, at most 60% as toxic as a naturally-occurring Clostridial toxin, at most 70% as toxic as a naturally-occurring Clostridial toxin, at most 80% as toxic as a naturally-occurring Clostridial toxin, at most 90% as toxic as a naturally-occurring Clostridial toxin or at most 95% as toxic as a naturally-occurring Clostridial toxin.

Another aspect of the present invention provides polynucleotide molecules encoding modified Clostridial toxins disclosed in the present specification. It is envisioned that any and all modified Clostridial toxin disclosed in the present specification can be encoded by a polynucleotide molecule.

Aspects of the present invention provide, in part polynucleotide molecules. As used herein, the term “polynucleotide molecule” is synonymous with “nucleic acid molecule” and means a polymeric form of nucleotides, such as, e.g., ribonucleotides and deoxyribonucleotides, of any length. It is envisioned that any and all polynucleotide molecules that can encode a modified Clostridial toxin disclosed in the present specification can be useful, including, without limitation naturally-occurring and non-naturally-occurring DNA molecules and naturally-occurring and non-naturally-occurring RNA molecules. Non-limiting examples of naturally-occurring and non-naturally-occurring DNA molecules include single-stranded DNA molecules, double-stranded DNA molecules, genomic DNA molecules, cDNA molecules, vector constructs, such as, e.g., plasmid constructs, phagmid constructs, bacteriophage constructs, retroviral constructs and artificial chromosome constructs. Non-limiting examples of naturally-occurring and non-naturally-occurring RNA molecules include single-stranded RNA, double stranded RNA and mRNA.

Thus, in an embodiment, a polynucleotide molecule encodes a modified Clostridial toxin disclosed in the present specification.

In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising an altered targeting domain disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding an altered targeting domain comprises a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a presynaptic membrane of a Clostridial toxin target cell. In an aspect of this embodiment, a polynucleotide molecule encoding a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a presynaptic membrane of a Clostridial toxin target cell comprises a naturally occurring variant, such as, e.g., an isoform or a subtype. In another aspect of this embodiment, a polynucleotide molecule encoding a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a presynaptic membrane of a Clostridial toxin target cell comprises a non-naturally occurring variant, such as, e.g., a conservative variant, a non-conservative variant or an active fragment, or any combination thereof. In other aspects of this embodiment, a polynucleotide molecule encoding a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a presynaptic membrane of a Clostridial toxin target cell comprises a TGFβ superfamily polypeptide, such as, e.g., a TGFβ, a BMPs, a GDF and an activin; a neurotrophin, such as, e.g., a NGF, a BDNF, a NT-3 and a NT-4/5; an axon guidance signaling molecule, such as, e.g., a netrin, a semaphroring and an ephrin; a neuroregulatory cytokine, such as, e.g., a CNTF, a GPA, a LIF, an interleukin, an onostatin M, a CT-1 and a CLC; a sugar binding protein, such as, e.g., a serum amyloid P, a β-glucanase, a sialidase, a lectin, a cryia, an insecticidal delta-endotoxin, an agglutinin, an abrin and a ricin; an IGF, such as, e.g., a IGF-1 and a IGF-2; a neurexin; a neuroleukin/AMF/MF; a TrkB; an EGF; a visceral gut peptide such as, e.g., a gastrin, a VIP, a bombesin; and a WNT, such as, e.g., a Frizzled.

In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising an altered targeting domain disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding an altered targeting domain comprises a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a postsynaptic membrane of a Clostridial toxin target cell. In an aspect of this embodiment, a polynucleotide molecule encoding a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a postsynaptic membrane of a Clostridial toxin target cell comprises a naturally occurring variant, such as, e.g., an isoform or a subtype. In another aspect of this embodiment, a polynucleotide molecule encoding a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a postsynaptic membrane of a Clostridial toxin target cell comprises a non-naturally occurring variant, such as, e.g., a conservative variant, a non-conservative variant or an active fragment, or any combination thereof. In other aspects of this embodiment, a polynucleotide molecule encoding a polypeptide that selectively binds to a non-Clostridial toxin receptor present on a postsynaptic membrane of a Clostridial toxin target cell comprises a Ng-CAM(L1), a N-CAM, a N-cadherin, an agrin-MUSK, and a basement membrane polypeptide, such as, e.g., laminin β-2.

In another embodiment, a polynucleotide molecule encodes, in part, a modified Clostridial toxin comprising a flexible spacer disclosed in the present specification. In an aspect of this embodiment, a polynucleotide molecule encoding a flexible spacer a G-spacer, a A-spacer of any combination thereof.

Well-established molecular biology techniques that may be necessary to make a polynucleotide molecule encoding a modified Clostridial toxin disclosed in the present specification including, but not limited to, procedures involving polymerase chain reaction (PCR) amplification, restriction enzyme reactions, agarose gel electrophoresis, nucleic acid ligation, bacterial transformation, nucleic acid purification, nucleic acid sequencing and recombination-based techniques are routine procedures well within the scope of one skilled in the art and from the teaching herein. Non-limiting examples of specific protocols necessary to make a polynucleotide molecule encoding a modified Clostridial toxin are described in e.g., MOLECULAR CLONING A LABORATORY MANUAL, supra, (2001); and CURRENT PROTOCOLS IN MOLECULAR BIOLOGY (Frederick M. Ausubel et al., eds. John Wiley & Sons, 2004). Additionally, a variety of commercially available products useful for making a polynucleotide molecule encoding a modified Clostridial toxin are widely available. These protocols are routine procedures well within the scope of one skilled in the art and from the teaching herein.

Another aspect of the present invention provides a method of producing a modified Clostridial toxin disclosed in the present specification, such method comprising the step of expressing a polynucleotide molecule encoding a modified Clostridial toxin in a cell. Another aspect of the present invention provides a method of producing a modified Clostridial toxin disclosed in the present specification, such method comprising the steps of introducing an expression construct comprising a polynucleotide molecule encoding a modified Clostridial toxin into a cell and expressing the expression construct in the cell.

The methods disclosed in the present specification include, in part, a modified Clostridial toxin. It is envisioned that any and all modified Clostridial toxins disclosed in the present specification can be produced using the methods disclosed in the present specification. It is also envisioned that any and all polynucleotide molecules encoding a modified Clostridial toxins disclosed in the present specification can be useful in producing a modified Clostridial toxins disclosed in the present specification using the methods disclosed in the present specification.

The methods disclosed in the present specification include, in part, an expression construct. An expression construct comprises a polynucleotide molecule disclosed in the present specification operably-linked to an expression vector useful for expressing the polynucleotide molecule in a cell or cell-free extract. A wide variety of expression vectors can be employed for expressing a polynucleotide molecule encoding a modified Clostridial toxin, including, without limitation, a viral expression vector; a prokaryotic expression vector; eukaryotic expression vectors, such as, e.g., a yeast expression vector, an insect expression vector and a mammalian expression vector; and a cell-free extract expression vector. It is further understood that expression vectors useful to practice aspects of these methods may include those which express a modified Clostridial toxin under control of a constitutive, tissue-specific, cell-specific or inducible promoter element, enhancer element or both. Non-limiting examples of expression vectors, along with well-established reagents and conditions for making and using an expression construct from such expression vectors are readily available from commercial vendors that include, without limitation, BD Biosciences-Clontech, Palo Alto, Calif.; BD Biosciences Pharmingen, San Diego, Calif.; Invitrogen, Inc, Carlsbad, Calif.; EMD Biosciences-Novagen, Madison, Wis.; QIAGEN, Inc., Valencia, Calif.; and Stratagene, La Jolla, Calif. The selection, making and use of an appropriate expression vector are routine procedures well within the scope of one skilled in the art and from the teachings herein.

Thus, aspects of this embodiment include, without limitation, a viral expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin; a prokaryotic expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin; a yeast expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin; an insect expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin; and a mammalian expression vector operably-linked to a polynucleotide molecule encoding a modified Clostridial toxin. Other aspects of this embodiment include, without limitation, expression constructs suitable for expressing a modified Clostridial toxin disclosed in the present specification using a cell-free extract comprising a cell-free extract expression vector operably linked to a polynucleotide molecule encoding a modified Clostridial toxin.

The methods disclosed in the present specification include, in part, introducing into a cell a polynucleotide molecule. A polynucleotide molecule introduced into a cell can be transiently or stably maintained by that cell. Stably-maintained polynucleotide molecules may be extra-chromosomal and replicate autonomously, or they may be integrated into the chromosomal material of the cell and replicate non-autonomously. It is envisioned that any and all methods for introducing a polynucleotide molecule disclosed in the present specification into a cell can be used. Methods useful for introducing a nucleic acid molecule into a cell include, without limitation, chemical-mediated transfection such as, e.g., calcium phosphate-mediated, diethyl-aminoethyl (DEAE) dextran-mediated, lipid-mediated, polyethyleneimine (PEI)-mediated, polylysine-mediated and polybrene-mediated; physical-mediated tranfection, such as, e.g., biolistic particle delivery, microinjection, protoplast fusion and electroporation; and viral-mediated transfection, such as, e.g., retroviral-mediated transfection, see, e.g., Introducing Cloned Genes into Cultured Mammalian Cells, pp. 16.1-16.62 (Sambrook & Russell, eds., Molecular Cloning A Laboratory Manual, Vol. 3, 3rd ed. 2001). One skilled in the art understands that selection of a specific method to introduce an expression construct into a cell will depend, in part, on whether the cell will transiently contain an expression construct or whether the cell will stably contain an expression construct. These protocols are routine procedures within the scope of one skilled in the art and from the teaching herein.

Adenoviruses, which are non-enveloped, double-stranded DNA viruses, are often selected for mammalian cell transduction because adenoviruses handle relatively large polynucleotide molecules of about 36 kb, are produced at high titer, and can efficiently infect a wide variety of both dividing and non-dividing cells, see, e.g., Wim T. J. M. C. Hermens et al., Transient gene transfer to neurons and glia: analysis of adenoviral vector performance in the CNS and PNS, 71 (1) J. Neurosci. Methods 85-98 (1997); and Hiroyuki Mizuguchi et al., Approaches for generating recombinant adenovirus vectors, 52(3) Adv. Drug Deliv. Rev. 165-176 (2001). Transduction using adenoviral-based system do not support prolonged protein expression because the nucleic acid molecule is carried from an episome in the cell nucleus, rather than being integrated into the host cell chromosome. Adenoviral vector systems and specific protocols for how to use such vectors are disclosed in, e.g., ViraPower™ Adenoviral Expression System (Invitrogen, Inc., Carlsbad, Calif.) and ViraPower™ Adenoviral Expression System Instruction Manual 25-0543 version A, Invitrogen, Inc., (Jul. 15, 2002); and AdEaSy™ Adenoviral Vector System (Stratagene, Inc., La Jolla, Calif.) and AdEaSy™ Adenoviral Vector System Instruction Manual 064004f, Stratagene, Inc.

Nucleic acid molecule delivery can also use single-stranded RNA retroviruses, such as, e.g., oncoretroviruses and lentiviruses. Retroviral-mediated transduction often produce transduction efficiencies close to 100%, can easily control the proviral copy number by varying the multiplicity of infection (MOI), and can be used to either transiently or stably transduce cells, see, e.g., Tiziana Tonini et al., Transient production of retroviral- and lentiviral-based vectors for the transduction of Mammalian cells, 285 Methods Mol. Biol. 141-148 (2004); Armin Blesch, Lentiviral and MLV based retroviral vectors for ex vivo and in vivo gene transfer, 33(2) Methods 164-172 (2004); Félix Recillas-Targa, Gene transfer and expression in mammalian cell lines and transgenic animals, 267 Methods Mol. Biol. 417-433 (2004); and Roland Wolkowicz et al., Lentiviral vectors for the delivery of DNA into mammalian cells, 246 Methods Mol. Biol. 391-411 (2004). Retroviral particles consist of an RNA genome packaged in a protein capsid, surrounded by a lipid envelope. The retrovirus infects a host cell by injecting its RNA into the cytoplasm along with the reverse transcriptase enzyme. The RNA template is then reverse transcribed into a linear, double stranded cDNA that replicates itself by integrating into the host cell genome. Viral particles are spread both vertically (from parent cell to daughter cells via the provirus) as well as horizontally (from cell to cell via virions). This replication strategy enables long-term persistent expression since the nucleic acid molecules of interest are stably integrated into a chromosome of the host cell, thereby enabling long-term expression of the protein. For instance, animal studies have shown that lentiviral vectors injected into a variety of tissues produced sustained protein expression for more than 1 year, see, e.g., Luigi Naldini et al., In vivo gene delivery and stable transduction of non-dividing cells by a lentiviral vector, 272(5259) Science 263-267 (1996). The Oncoretroviruses-derived vector systems, such as, e.g., Moloney murine leukemia virus (MoMLV), are widely used and infect many different non-dividing cells. Lentiviruses can also infect many different cell types, including dividing and non-dividing cells and possess complex envelope proteins, which allows for highly specific cellular targeting.

8. The modified Clostridial toxin according to 1, wherein the Clostridial toxin enzymatic domain is selected from the group consisting of a BoNT/A enzymatic domain, a BoNT/B enzymatic domain, a BoNT/C1 enzymatic domain, a BoNT/D enzymatic domain, a BoNT/E enzymatic domain, a BoNT/F enzymatic domain, a BoNT/G enzymatic domain and a TeNT enzymatic domain.

9. The modified Clostridial toxin according to 1, wherein the Clostridial toxin translocation domain is selected from the group consisting of a BoNT/A translocation domain, a BoNT/B translocation domain, a BoNT/C1 translocation domain, a BoNT/D translocation domain, a BoNT/E translocation domain, a BoNT/F translocation domain, a BoNT/G translocation domain and a TeNT translocation domain.

10. The modified Clostridial toxin according to 1, wherein the translocation facilitating domain is a Clostridial toxin translocation facilitating domain.

23. The modified Clostridial toxin according to 1, wherein the altered targeting domain is selected from the group consisting of a glucagon like hormone, a neurohormone, a neuroregulatory cytokine, a neurotrophin, a growth factor, an axon guidance signaling molecule, a sugar binding protein, a ligand that selectively binds a neurexin, a ligand for neurexin-2α, a ligand for neurexin-2β, a ligand for neurexin-3α, a ligand for neurexin-3β, a WNT, Ng-CAM(L1), NCAM, N-cadherin, Agrin-MUSK, a basement membrane polypeptide, and a variant of any of the foregoing polypeptides, such that the targeting domain is capable of executing a cell binding step of a Clostridial toxin intoxication process.

26. The modified Clostridial toxin according to 23, wherein the altered targeting domain comprises a neurohormone selected from the group consisting of corticotropin-releasing hormone (CCRH) and parathyroid hormone (PTH).

37. The modified Clostridial toxin according to 23, wherein the altered targeting domain comprises a ligand that binds a polypeptide selected from the group consisting of neurexin-1α, neurexin-1β, neurexin-2α, neurexin-2β, neurexin-3α and neurexin-3

51. The polynucleotide molecule according to 43, wherein the polynucleotide molecule encoding the altered targeting domain is selected from the group consisting of a polynucleotide molecule encoding a glucagon like hormone, a neurohormone, a neuroregulatory cytokine, a neurotrophin, a growth factor, an axon guidance signaling molecule, a sugar binding protein, a ligand that selectively binds a neurexin, a ligand for neurexin-2α, a ligand for neurexin-2β, a ligand for neurexin-3α, a ligand for neurexin-3β, a WNT, Ng-CAM(L1), NCAM, N-cadherin, Agrin-MUSK, a basement membrane polypeptide, and a variant of any of the foregoing polypeptides, such that the targeting domain is capable of executing a cell binding step of a Clostridial toxin intoxication process.

53. The polynucleotide molecule according to 43, wherein the polynucleotide molecule encoding the altered targeting domain comprises a neurohormone selected from the group consisting of a polynucleotide molecule encoding corticotropin-releasing hormone (CCRH) and parathyroid hormone (PTH).

59. The polynucleotide molecule according to 43, wherein the polynucleotide molecule encoding the altered targeting domain comprises a ligand that binds a polypeptide selected from the group consisting of neurexin-1α, neurexin-1β, neurexin-2α, neurexin-2β, neurexin-3α and neurexin-3β.

61. A method of producing a modified Clostridial toxin comprising the step of expressing a polynucleotide molecule encoding a modified Clostridial toxin in a cell, the polynucleotide molecule comprising:

64. The method according to 63, wherein the polynucleotide molecule is any one of the polynucleotide molecules of 43.

EXAMPLES

The following non-limiting examples are provided for illustrative purposes only in order to facilitate a more complete understanding of disclosed embodiments and are in no way intended to limit any of the embodiments disclosed in the present specification.

This example illustrates how to make a modified Clostridial toxin disclosed in the present specification comprising a translocation facilitating domain and an altered targeting domain located at the amino terminus of the modified toxin.

A polynucleotide molecule based on BoNT/A-AP4A-GRPP (SEQ ID NO: 194) will be synthesized using standard procedures (BlueHeron® Biotechnology, Bothell, Wash.). This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A HCC targeting domain, with amino acids 21-50 of SEQ ID NO: 9, a GRPP targeting domain, and has the general domain arrangement of FIG. 4A. Oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides will be hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule will be cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-AP4A-GRPP. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (Applied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (Applied Biosystems, Foster City, Calif.).

If desired, an expression optimized polynucleotide molecule based on BoNT/A-AP4A-GRPP (SEQ ID NO: 194) can be synthesized in order to improve expression in an Escherichia coli strain. The polynucleotide molecule encoding the BoNT/A-AP4A-GRPP will be modified to 1) contain synonymous codons typically present in native polynucleotide molecules of an Escherichia coli strain; 2) contain a G+C content that more closely matches the average G+C content of native polynucleotide molecules found in an Escherichia coli strain; 3) reduce polymononucleotide regions found within the polynucleotide molecule; and/or 4) eliminate internal regulatory or structural sites found within the polynucleotide molecule, see, e.g., Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type E, International Patent Publication WO 2006/011966 (Feb. 2, 2006); Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type A, International Patent Publication WO 2006/017749 (Feb. 16, 2006). Once sequence optimization is complete, oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides are hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule is cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-AP4A-GRPP. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (Applied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (Applied Biosystems, Foster City, Calif.). If so desired, expression optimization to a different organism, such as, e.g., a yeast strain, an insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

To construct pET29/BoNT/A-AP4A-GRPP, a pUCBHB1/BoNT/A-AP4A-GRPP construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-AP4A-GRPP; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-AP4A-GRPP. The ligation mixture will be transformed into chemically competent E. coli DH5α cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 μg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-AP4A-GRPP operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

To construct a BoNT/A-AP4A-GRPP that will replace the BoNT/A translocation facilitating domain with another Clostridial toxin translocation facilitating domain, a translocation facilitating domain of BoNT/B will be introduced into the BoNT/A-AP4A-GRPP as described above using a Splicing by Overlapping ends polymerase chain reaction (SOE-PCR) procedure, see, e.g., R. M. Horton et al., Engineering hybrid genes without the use of restriction enzymes: gene splicing by overlapping extension, 77(1) Gene 61-68 (1989); and R. M. Horton, PCR-mediated recombination and mutagenesis. SOEing together tailor-made genes, 3(2) Mol. Biotechnol. 93-99 (1995). A nucleic acid fragment comprising a region encoding amino acids 859 to 1097 of BoNT/B (SEQ ID NO: 2) will be operably-linked by SOE-PCR to replace the region corresponding to the BoNT/A translocation facilitating domain comprising amino acids 874-1110 of SEQ ID NO: 1 of the BoNT/A-AP4A-GRPP and will be subcloned into a pCR2.1 vector using the TOPO® TA cloning method (Invitrogen, Inc, Carlsbad, Calif.). The forward and reverse oligonucleotide primers used for these reactions are designed to include unique restriction enzyme sites useful for subsequent subcloning steps. The resulting construct will be digested with restriction enzymes that 1) will excise the polynucleotide molecule containing the entire open reading frame encoding the modified BoNT/A-AP4A-GRPP; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). The resulting restriction fragment will be purified by the QIAquick Gel Extraction Kit (QIAGEN, Inc., Valencia, Calif.), and will be subcloned using a T4 DNA ligase procedure into a pET29 vector. This cloning strategy yielded a pET29 expression construct encoding a BoNT/A-AP4A-GRPP comprising a BoNT/B translocation facilitating domain.

A polynucleotide molecule based on BoNT/A-AP4B-GRPP (SEQ ID NO: 195) will be synthesized and cloned into a pUCBHB1 vector as described in Example 1a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A HCC targeting domain, with amino acids 21-50 of SEQ ID NO: 9, a GRPP targeting domain, and has the general domain arrangement of FIG. 4B. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

This example illustrates how to make a modified Clostridial toxin disclosed in the present specification comprising a translocation facilitating domain and an altered targeting domain located between two other domains of the modified toxin.

A polynucleotide molecule based on BoNT/A-CP5A-GRPP (SEQ ID NO: 196) will be synthesized using standard procedures (BlueHeron® Biotechnology, Bothell, Wash.). This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A HCC targeting domain, with amino acids 21-50 of SEQ ID NO: 9, a GRPP targeting domain, and has the general domain arrangement of FIG. 5A. Cleavage of an enterokinse cleavage site used to form the di-chain toxin also exposes the first amino acid of the GRPP targeting domain. Oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides will be hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule will be cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-CP5A-GRPP. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (Applied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (Applied Biosystems, Foster City, Calif.).

If desired, an expression optimized polynucleotide molecule based on BoNT/A-CP5A-GRPP (SEQ ID NO: 196) can be synthesized in order to improve expression in an Escherichia coli strain. The polynucleotide molecule encoding the BoNT/A-CP5A-GRPP will be modified to 1) contain synonymous codons typically present in native polynucleotide molecules of an Escherichia coli strain; 2) contain a G+C content that more closely matches the average G+C content of native polynucleotide molecules found in an Escherichia coli strain; 3) reduce polymononucleotide regions found within the polynucleotide molecule; and/or 4) eliminate internal regulatory or structural sites found within the polynucleotide molecule, see, e.g., Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type E, International Patent Publication WO 2006/011966 (Feb. 2, 2006); Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type A, International Patent Publication WO 2006/017749 (Feb. 16, 2006). Once sequence optimization is complete, oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides are hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule is cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-CP5A-GRPP. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (CP5Aplied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (CP5Aplied Biosystems, Foster City, Calif.). If so desired, expression optimization to a different organism, such as, e.g., a yeast strain, an insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

To construct pET29/BoNT/A-CP5A-GRPP, a pUCBHB1/BoNT/A-CP5A-GRPP construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-CP5A-GRPP; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-CP5A-GRPP. The ligation mixture will be transformed into chemically competent E. coli DH5α cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 μg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-CP5A-GRPP operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

To construct a BoNT/A-CP5A-GRPP that will replace the BoNT/A translocation facilitating domain with another Clostridial toxin translocation facilitating domain, a translocation facilitating domain of BoNT/B will be introduced into the BoNT/A-CP5A-GRPP as described above using a Splicing by Overlapping ends polymerase chain reaction (SOE-PCR) procedure, see, e.g., R. M. Horton et al., Engineering hybrid genes without the use of restriction enzymes: gene splicing by overlapping extension, 77(1) Gene 61-68 (1989); and R. M. Horton, PCR-mediated recombination and mutagenesis. SOEing together tailor-made genes, 3(2) Mol. Biotechnol. 93-99 (1995). A nucleic acid fragment comprising a region encoding amino acids 859 to 1097 of BoNT/B (SEQ ID NO: 2) will be operably-linked by SOE-PCR to replace the region corresponding to the BoNT/A translocation facilitating domain comprising amino acids 874-1110 of SEQ ID NO: 1 of the BoNT/A-CP5A-GRPP and will be subcloned into a pCR2.1 vector using the TOPO® TA cloning method (Invitrogen, Inc, Carlsbad, Calif.). The forward and reverse oligonucleotide primers used for these reactions are designed to include unique restriction enzyme sites useful for subsequent subcloning steps. The resulting construct will be digested with restriction enzymes that 1) will excise the polynucleotide molecule containing the entire open reading frame encoding the modified BoNT/A-CP5A-GRPP; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). The resulting restriction fragment will be purified by the QIAquick Gel Extraction Kit (QIAGEN, Inc., Valencia, Calif.), and will be subcloned using a T4 DNA ligase procedure into a pET29 vector. This cloning strategy yielded a pET29 expression construct encoding a BoNT/A-CP5A-GRPP comprising a BoNT/B translocation facilitating domain.

A polynucleotide molecule based on BoNT/A-CP5B-GRPP (SEQ ID NO: 197) will be synthesized and cloned into a pUCBHB1 vector as described in Example 1a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A HCC targeting domain, with amino acids 21-50 of SEQ ID NO: 9, a GRPP targeting domain, and has the general domain arrangement of FIG. 5B. Cleavage of an enterokinse cleavage site used to form the di-chain toxin also exposes the first amino acid of the GRPP targeting domain. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

This example illustrates how to make a modified Clostridial toxin disclosed in the present specification comprising a translocation facilitating domain and an altered targeting domain located at the carboxyl terminus of the modified toxin.

A polynucleotide molecule based on BoNT/A-XP6A-GRPP (SEQ ID NO: 198) will be synthesized using standard procedures (BlueHeron® Biotechnology, Bothell, Wash.). This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A HCC targeting domain, with amino acids 21-50 of SEQ ID NO: 9, a GRPP targeting domain, and has the general domain arrangement of FIG. 6A. Oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides will be hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule will be cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-XP6A-GRPP. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (Applied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (Applied Biosystems, Foster City, Calif.).

If desired, an expression optimized polynucleotide molecule based on BoNT/A-XP6A-GRPP (SEQ ID NO: 198) can be synthesized in order to improve expression in an Escherichia coli strain. The polynucleotide molecule encoding the BoNT/A-XP6A-GRPP will be modified to 1) contain synonymous codons typically present in native polynucleotide molecules of an Escherichia coli strain; 2) contain a G+C content that more closely matches the average G+C content of native polynucleotide molecules found in an Escherichia coli strain; 3) reduce polymononucleotide regions found within the polynucleotide molecule; and/or 4) eliminate internal regulatory or structural sites found within the polynucleotide molecule, see, e.g., Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type E, International Patent Publication WO 2006/011966 (Feb. 2, 2006); Lance E. Steward et al., Optimizing Expression of Active Botulinum Toxin Type A, International Patent Publication WO 2006/017749 (Feb. 16, 2006). Once sequence optimization is complete, oligonucleotides of 20 to 50 bases in length are synthesized using standard phosphoramidite synthesis. These oligonucleotides are hybridized into double stranded duplexes that are ligated together to assemble the full-length polynucleotide molecule. This polynucleotide molecule is cloned using standard molecular biology methods into a pUCBHB1 vector at the SmaI site to generate pUCBHB1/BoNT/A-XP6A-GRPP. The synthesized polynucleotide molecule is verified by sequencing using Big Dye Terminator™ Chemistry 3.1 (Applied Biosystems, Foster City, Calif.) and an ABI 3100 sequencer (Applied Biosystems, Foster City, Calif.). If so desired, expression optimization to a different organism, such as, e.g., a yeast strain, an insect cell-line or a mammalian cell line, can be done, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

To construct pET29/BoNT/A-XP6A-GRPP, a pUCBHB1/BoNT/A-XP6A-GRPP construct will be digested with restriction endonucleases that 1) will excise the polynucleotide molecule encoding the open reading frame of BoNT/A-XP6A-GRPP; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). This insert will be subcloned using a T4 DNA ligase procedure into a pET29 vector that is digested with appropriate restriction endonucleases to yield pET29/BoNT/A-XP6A-GRPP. The ligation mixture will be transformed into chemically competent E. coli DH5α cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat shock method, will be plated on 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 μg/mL of Kanamycin, and will be placed in a 37° C. incubator for overnight growth. Bacteria containing expression constructs will be identified as Kanamycin resistant colonies. Candidate constructs will be isolated using an alkaline lysis plasmid mini-preparation procedure and will be analyzed by restriction endonuclease digest mapping to determine the presence and orientation of the insert. This cloning strategy will yield a pET29 expression construct comprising the polynucleotide molecule encoding the BoNT/A-XP6A-GRPP operably-linked to a carboxyl terminal polyhistidine affinity binding peptide.

To construct a BoNT/A-XP6A-GRPP that will replace the BoNT/A translocation facilitating domain with another Clostridial toxin translocation facilitating domain, a translocation facilitating domain of BoNT/B will be introduced into the BoNT/A-XP6A-GRPP as described above using a Splicing by Overlapping ends polymerase chain reaction (SOE-PCR) procedure, see, e.g., R. M. Horton et al., Engineering hybrid genes without the use of restriction enzymes: gene splicing by overlapping extension, 77(1) Gene 61-68 (1989); and R. M. Horton, PCR-mediated recombination and mutagenesis. SOEing together tailor-made genes, 3(2) Mol. Biotechnol. 93-99 (1995). A nucleic acid fragment comprising a region encoding amino acids 859 to 1097 of BoNT/B (SEQ ID NO: 2) will be operably-linked by SOE-PCR to replace the region corresponding to the BoNT/A translocation facilitating domain comprising amino acids 874-1110 of SEQ ID NO: 1 of the BoNT/A-XP6A-GRPP and will be subcloned into a pCR2.1 vector using the TOPO® TA cloning method (Invitrogen, Inc, Carlsbad, Calif.). The forward and reverse oligonucleotide primers used for these reactions are designed to include unique restriction enzyme sites useful for subsequent subcloning steps. The resulting construct will be digested with restriction enzymes that 1) will excise the polynucleotide molecule containing the entire open reading frame encoding the modified BoNT/A-XP6A-GRPP; and 2) will enable this polynucleotide molecule to be operably-linked to a pET29 vector (EMD Biosciences-Novagen, Madison, Wis.). The resulting restriction fragment will be purified by the QIAquick Gel Extraction Kit (QIAGEN, Inc., Valencia, Calif.), and will be subcloned using a T4 DNA ligase procedure into a pET29 vector. This cloning strategy yielded a pET29 expression construct encoding a BoNT/A-XP6A-GRPP comprising a BoNT/B translocation facilitating domain.

A polynucleotide molecule based on BoNT/A-XP6B-GRPP (SEQ ID NO: 199) will be synthesized and cloned into a pUCBHB1 vector as described in Example 1a. This polynucleotide molecule encodes a BoNT/A modified to replace amino acids 1111-1296 of SEQ ID NO: 1, a BoNT/A HCC targeting domain, with amino acids 21-50 of SEQ ID NO: 9, a GRPP targeting domain, and has the general domain arrangement of FIG. 6B. If so desired, expression optimization to a different organism, such as, e.g., a bacteria, a yeast strain, an insect cell-line or a mammalian cell line, can be done as described above, see, e.g., Steward, supra, (Feb. 2, 2006); and Steward, supra, (Feb. 16, 2006).

Example 4Expression of Modified Clostridial Toxins in a Bacterial Cell

The following example illustrates a procedure useful for expressing any of the modified Clostridial toxins disclosed in the present specification in a bacterial cell.

An expression construct, such as, e.g., any of the expression constructs in Examples 1-5, is introduced into chemically competent E. coli BL21 (DE3) cells (Invitrogen, Inc, Carlsbad, Calif.) using a heat-shock transformation protocol. The heat-shock reaction is plated onto 1.5% Luria-Bertani agar plates (pH 7.0) containing 50 μg/mL of Kanamycin and is placed in a 37° C. incubator for overnight growth. Kanamycin-resistant colonies of transformed E. coli containing the expression construct are used to inoculate a baffled flask containing 3.0 mL of PA-0.5G media containing 50 μg/mL of Kanamycin which is then placed in a 37° C. incubator, shaking at 250 rpm, for overnight growth. The resulting overnight starter culture is in turn used to inoculate a 3 L baffled flask containing ZYP-5052 autoinducing media containing 50 μg/mL of Kanamycin at a dilution of 1:1000. Culture volumes ranged from about 600 mL (20% flask volume) to about 750 mL (25% flask volume). These cultures are grown in a 37° C. incubator shaking at 250 rpm for approximately 5.5 hours and are then transferred to a 16° C. incubator shaking at 250 rpm for overnight expression. Cells are harvested by centrifugation (4,000 rpm at 4° C. for 20-30 minutes) and are used immediately, or stored dry at −80° C. until needed.

For purification of a modified Clostridial toxin using a FPLC desalting column, a HiPrep™ 26/10 size exclusion column (Amersham Biosciences, Piscataway, N.J.) is pre-equilibrated with 80 mL of 4° C. Column Buffer (50 mM sodium phosphate, pH 6.5). After the column is equilibrated, a modified Clostridial toxin sample is applied to the size exclusion column with an isocratic mobile phase of 4° C. Column Buffer and at a flow rate of 10 mL/minute using a BioLogic DuoFlow chromatography system (Bio-Rad Laboratories, Hercules, Calif.). The desalted modified Clostridial toxin sample is collected as a single fraction of approximately 7-12 mL.

For purification of a modified Clostridial toxin using a FPLC ion exchange column, a modified Clostridial toxin sample that has been desalted following elution from an IMAC column is applied to a 1 mL Q1™ anion exchange column (Bio-Rad Laboratories, Hercules, Calif.) using a BioLogic DuoFlow chromatography system (Bio-Rad Laboratories, Hercules, Calif.). The sample is applied to the column in 4° C. Column Buffer (50 mM sodium phosphate, pH 6.5) and is eluted by linear gradient with 4° C. Elution Buffer (50 mM sodium phosphate, 1 M sodium chloride, pH 6.5) as follows: step 1, 5.0 mL of 5% Elution Buffer at a flow rate of 1 mL/minute; step 2, 20.0 mL of 5-30% Elution Buffer at a flow rate of 1 mL/minute; step 3, 2.0 mL of 50% Elution Buffer at a flow rate of 1.0 mL/minute; step 4, 4.0 mL of 100% Elution Buffer at a flow rate of 1.0 mL/minute; and step 5, 5.0 mL of 0% Elution Buffer at a flow rate of 1.0 mL/minute. Elution of modified Clostridial toxin from the column is monitored at 280, 260, and 214 nm, and peaks absorbing above a minimum threshold (0.01 au) at 280 nm are collected. Most of the modified Clostridial toxin will elute at a sodium chloride concentration of approximately 100 to 200 mM. Average total yields of modified Clostridial toxin will be determined by a Bradford assay.

Although aspects of the present invention have been described with reference to the disclosed embodiments, one skilled in the art will readily appreciate that the specific examples disclosed are only illustrative of these aspects and in no way limit the present invention. Various modifications can be made without departing from the spirit of the present invention.